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There are 103 questions tagged under Energy & Work.

1

### Q:

A block of mass m slides down a hill of height h which makes a 30° angle with the horizontal. Assuming zero friction along the hill, what is the velocity of the block at the bottom of the hill?

√(2gh)sin(30°)

√(2gh)cos(30°)

√(2gh)

### D

√(mgh)

Tags: Energy & Work | Kinematics |

2

### Q:

A block of mass m undergoes simple harmonic motion on a frictionless surface. The potential energy of the system is zero when the system is in equilibrium and has a maximum value of 100 joules. When the magnitude of the displacement of the block is maximal, what is its instantaneous kinetic energy?

0 J

25 J

50 J

### D

100 J

Tags: Energy & Work |

3

### Q:

An aeroplane flying at 50 m/s drops a package of mass 5 kg from a height of 100 m. What is the total energy of the package at the moment before the package makes contact with the Earth? Neglect air resistance.

625 J

5000 J

6250 J

### D

11250 J

Tags: Energy & Work |

4

### Q:

A point charge Q moves into an electric field E. A team of scientists want to see the behavior of the charge at the line labeled Z. Lab funds are very limited and it is desired to minimize energy costs. Which of the following paths, A or B, should the scientists choose in order to minimize the energy inputted?

### A

Both paths are equal in energetic input.

### B

Path A will minimize costs because it is the shortest path from the point charge to the line Z.

### C

Path B will minimize costs because it avoids going directly in the opposing electric field.

### D

Path A will minimize costs because it goes parallel to the electric field.

Tags: Energy & Work | Electrostatics |

5

### Q:

Freezing of a substance occurs when molecules lose a sufficient amount of

### A

potential energy.

kinetic energy.

chemical energy.

### D

surface tension.

Tags: Energy & Work |

6

### Q:

Which of the following describes an exothermic reaction?

### A

the value of H is negative, and the products have more chemical potential energy than the reactants

### B

the value of H is negative, and the products have less chemical potential energy than the reactants

### C

the value of H is positive, and the products have more chemical potential energy than the reactants

### D

the value of H is positive, and the products have less chemical potential energy than the reactants

Tags: Energy & Work |

7

### Q:

Moving a 2 x 10-6 coulomb point charge from point X to point Y in an electric field requires 8 x 10-4 joule of work. The potential difference between points X and Y is approximately

4 x 10-2 V

4 x 102 V

4 x 103 V

### D

4 x 10-3 V

Tags: Energy & Work | Electrostatics |

8

### Q:

A 3.0-kilogram block is initially at rest on a frictionless, horizontal surface. The block is moved 8.0 meters in 2.0 seconds by the application of a 12-newton horizontal force. What is the average power developed while moving the block?

24 W

32 W

48 W

### D

96 W

Tags: Energy & Work |

9

### Q:

Chlorophyll absorbs maximally in red and blue wavelengths. Consider a genetically modified plant which expresses an enzyme that emits red and blue light using energy from the conversion of ATP to ADP. If the plant were placed in complete darkness, would it be able to grow from the light energy emitted by the enzymes?

### A

No, because the amount of energy absorbed by the plant must be greater than or equal to the energy involved in the metabolism of the plant, impossible under the described conditions since the light energy emitted must be less than the energy involved in the metabolism of the plant.

### B

No, because the amount of energy absorbed by the plant must be less than or equal to the energy involved in the metabolism of the plant, yet the energy emitted by the enzymes is greater than the the energy involved in the metabolism of the plant.

### C

Yes, because the energy emitted from the enzyme is greater than the required energy for metabolic metabolic processes required to produce the light.

### D

Yes, because only a small amount of light energy is needed to stimulate growth; the remainder can come from the soil, air, and water.

Tags: Energy & Work |

10

### Q:

A spring with k = 50 N/m is compressed 10 cm. The full potential energy of the spring is imparted onto a ball of mass 50 g. What is the velocity at which the ball is released from the spring?

√6.25 m/s

√10 m/s

10 m/s

### D

100 m/s

Tags: Energy & Work |

11

### Q:

A pendulum moves with periodic motion. At the maximal height of motion, it is true that:

### A

Kinetic energy is at a maximum, potential energy is at a minimum

### B

Kinetic energy is at a minimum, potential energy is at a maximum

### C

Both kinetic and potential energies are at a maximum

### D

Both kinetic and potential energies are at a minimum

Tags: Energy & Work |

12

### Q:

Chlorophyll absorbs maximally in red and blue wavelengths. Consider a genetically modified plant which expresses an enzyme that emits red and blue light using energy from the conversion of ATP to ADP. If the plant were placed in complete darkness, would it be able to grow sustainably from the light energy emitted by the enzymes?

### A

No, because the amount of energy absorbed by the plant must be greater than or equal to the energy involved in the metabolism of the plant, impossible under the described conditions since the light energy emitted must be less than the energy involved in the metabolism of the plant.

### B

No, because the amount of energy absorbed by the plant must be less than or equal to the energy involved in the metabolism of the plant, yet the energy emitted by the enzymes is greater than the the energy involved in the metabolism of the plant.

### C

Yes, because the energy emitted from the enzyme is greater than the required energy for metabolic metabolic processes required to produce the light.

### D

Yes, because only a small amount of light energy is needed to stimulate growth; the remainder can come from the soil, air, and water.

Tags: Enzyme Structure and Function | Energy & Work |

13

### Q:

An object of 3 kg enters is accelerated on a rail to 1000 m/s. The object is released and travels freely for 100 m before impacting a lead wall. At the moment of impact, 250,000 J are released. How much energy was lost from the time of release until the time of impact?

0 J

250,000 J

1,250,000 J

### D

1,500,000 J

Tags: Energy & Work |

14

### Q:

Heat is added to a piece of ice at 760 Torr (standard atmospheric pressure) at 0 degrees Celsius. Which of the following is true?

### A

Entropy of the system decreases

### B

The covalent bonds between the oxygens and the hydrogens are broken

### C

Temperature increases before all of the ice has melted

### D

There is no increase in kinetic energy of the molecules

Tags: Energy & Work |

15

### Q:

Which of the following is not included when describing the internal energy of a molecule?

### A

Vibrational energy

### B

Rotational energy

### C

Mechanical energy

### D

Translational energy

Tags: Energy & Work |

16

### Q:

The efficiency of a heat engine is calculated by the formula Efficiency = 1 - (T1/T2) where T1 is the cold reservoir and T2 is the hot reservoir. Which of the following will maximize efficiency of the system?

### A

In the cold reservoir, increasing pressure while keeping volume constant

### B

In the hot reservoir, decreasing pressure proportionally to a volume increase.

### C

In the cold reservoir, decreasing pressure while keeping volume constant

### D

Decreasing pressure in both the hot and cold reservoirs by the same proportions

Tags: Energy & Work |

17

### Q:

Which of the following units is not a function of time?

Velocity

Power

### C

Electrical Conductivity

### D

Energy

Tags: Kinematics | Energy & Work | Circuits |

18

### Q:

A force of 5.0 x 103 N is applied to a moving object of mass 50 kg. The object stops within 20 m. How much work has been done on the object?

2.0 x 103

1.0 x 105

5.0 x 106

### D

The question cannot be answered without knowing the initial velocity of the object.

Tags: Energy & Work |

19

### Q:

Which of the following does not correctly represent Power?

P = I2R

P = IR2/V

P = IV

### D

P = V2/R

Tags: Energy & Work |

20

### Q:

What is the energy required to run a 35 W light bulb for 1 minute?

35 J

35/60 J

210 J

### D

2100 J

Tags: Energy & Work |

21

### Q:

The increase in temperature due to friction is due to

Conduction

Convection

### D

None of the above

Tags: Energy & Work |

22

### Q:

A mass lies on a horizontal, frictionless beam and is attached to a horizontal spring with spring constant k. At full extension, the potential energy of the system is U while the kinetic energy, K, of the system is 0. What is the ratio of the potential energy to kinetic energy when the spring is at half its full extension, assuming the mass is released from full extension?

1:3

1:4

4:1

### D

3:1

Tags: Energy & Work | Quantitative Skills |

23

### Q:

Which of the following is equivalent to power?

joule/s2

watt/s2

N*m/s

### D

kg*m/s2

Tags: Energy & Work |

24

### Q:

A ball is launched from a height of 10 m at an angle of 30° to the horizontal. The kinetic energy of the ball upon launch is 500 J, and its mass is 10 kg. Neglecting friction, what is the kinetic energy of the ball on the instant it hits the ground at a height of 0 m? Assume g = 10 m/s2.

0 J

500 J

1500 J

### D

Impossible to determine with the information given.

Tags: Energy & Work |

25

### Q:

How much work is done on a 100kg block when a force of 200 N is applied to move the block a total distance of 15 m along a horizontal, frictionless surface? Assume g = 10 m/s2.

1.5 x 103 J

3 x 103 J

1.5 x 104 J

### D

3 x 105 J

Tags: Energy & Work |

26

### Q:

A person pushes a 200N cart filled with a 40N weight. After one minute of pushing, the cart has traveled 10 meters. What was the power output of the person?

20 W

24 W

36 W

### D

40 W

Tags: Energy & Work |

27

### Q:

Liquid is dropped from a height of 100 m. This particular liquid has a specific heat capacity of 500 J/kg*degrees Celsius. What is the rise in liquid temperature if all potential energy was converted into heat? Assume g=10 m/s^2.

### A

1 degrees Celsius

### B

2 degrees Celsius

### C

1.5 degrees Celsius

### D

5 degrees Celsius

Tags: Energy & Work | Fluids |

28

### Q:

A 25 cm spring is stretched by 3 cm by a pulling force of 9 N. If a pulling force of 21 N is applied (assuming the spring obeys Hooke's Law), how long is the spring then?

7 cm

12 cm

28 cm

### D

32 cm

Tags: Energy & Work | Quantitative Skills |

29

### Q:

What is the energy required to run a 100 W machine for one hour?

1 kJ

100 kJ

60 kJ

### D

360 kJ

Tags: Energy & Work | Quantitative Skills |

30

### Q:

When a horizontal 10 N force moves a 100 kg object across a horizontal distance of 40 m, how much work is done?

400 J

1000 J

4000 J

### D

40000 J

Tags: Energy & Work | Quantitative Skills |

31

### Q:

Which of the following is a "process quantity"?

Initial energy

Mechanical work

Enthalpy

### D

Entropy

Tags: Energy & Work |

32

### Q:

The kinetic energy of a group of molecules is directly reflected in which of the following parameters?

Pressure

Volume

Temperature

### D

Viscosity

Tags: Energy & Work |

33

### Q:

A sled on a horizontal plane has a massless rocket attached which provides a force of F in the +x direction for exactly 100 m. The frictional force B is equal to F at velocity V of the sled, and the velocity of the sled remains constant for the full 100 m during which F = B. How much work is done on the sled by the force of friction during the 100 m slide?

100B

100/B

B/100

### D

0

Tags: Energy & Work | Quantitative Skills |

34

### Q:

An ideal gas does work on the surroundings and undergoes an expansion from 10 L to 20 L. The external pressure is constant at 1 atm. The surroundings did 1000 work on the gas. What was the change in the internal energy of the gas? (1 L*atm = 100 J)

-1000 J

1000 J

0 J

### D

2000 J

Tags: Energy & Work | Gases | Quantitative Skills |

35

### Q:

How much more force must a person use to lift a 5 kg box up a height of 5 meters than to push it up the same height using a ramp that has a slope 15 meters long?

### A

the same amount of force

### B

2 times more force

### C

3 times more force

### D

4 times more force

Tags: Energy & Work | Quantitative Skills |

36

### Q:

A triangular ramp has a width of 3 meters and height of 4 meters. If the height of the ramp increases to 12 meters while maintaining the same width, how much more work is required to bring an object from the ground to the top of the ramp?

### A

1 times more work

### B

2 times more work

### C

3 times more work

### D

4 times more work

Tags: Energy & Work | Quantitative Skills |

37

### Q:

A 5-Coulomb charge moves 10 m down a 50 N/C electric field. How much work was done to move the charge down the field?

1 J

25 J

100 J

### D

2500 J

Tags: Energy & Work | Electrostatics | Quantitative Skills |

38

### Q:

A spring oscillates on a horizontal frictionless surface. At the end of the spring is attached a block of mass M. For any given spring extension, by how much does the spring potential energy change if the mass M is doubled to 2M?

### A

The energy halves.

### B

The energy remains the same.

### C

The energy doubles.

### D

The energy quandruples.

Tags: Energy & Work | Periodic Motion | Quantitative Skills |

39

### Q:

A sound is emitted at point A in space, and radiates as a sphere in all directions outward. The total energy emitted by the sound at point A is 100 W. What is the total energy of the entire sound wave at a distance d from point A? Assume no friction.

100/d W

100/d2 W

100d2 W

### D

100 W

Tags: Energy & Work | Sound | Quantitative Skills |

40

### Q:

A 5kg block slides down a frictionless incline of 30°. The moment it reaches 1 m/s down the incline, it hits a rough surface. What is the minimum coefficient of kinetic friction of the surface for it to stop the block before it reaches the bottom of the incline?

2/(5√3)

2/5

(√3)/2

### D

There is not enough information to answer the question.

Tags: Energy & Work | Quantitative Skills |

41

### Q:

A block slides across a plane for 15 m during which time it encounters a constant force of 100 N. If the average velocity of the block across the plane is 5 m/s, what is the power exerted on the block in Watts?

200 W

300 W

500 W

### D

The question cannot be answered with the information given.

Tags: Energy & Work | Quantitative Skills |

42

### Q:

What is the final velocity of a block traveling down a 5-m long frictionless incline at an angle of 18 degrees to the horizontal? Assume its starting velocity was 0 m/s at the top of the incline.

5.4 m/s

7.1 m/s

9.7 m/s

### D

there is not enough information to answer the question

Tags: Energy & Work | Quantitative Skills |

43

### Q:

The escape velocity is the velocity at which the gravitational potential energy of an object is equal to its kinetic energy and reflects the speed at which an object must move in order to escape the gravitational influence of the surface on which it rests. Which of the following accurately reflects the equation for the escape velocity of any object?

√(2GMh/r)

√(2GM/r2)

√(2GMm/r2)

### D

√(2GM/r)

Tags: Forces | Energy & Work |

44

### Q:

Which of the following has units of Newton Meters?

I. Torque
II. Energy
III. Work

I and II only

II and III only

III only

### D

I, II, and III

Tags: Energy & Work |

45

### Q:

On which of the following frictionless slides would the velocity of the object be the greatest at the bottom of the slide?

### D

The velocity at the bottom will be the same for all three slides.

Tags: Energy & Work |

46

### Q:

A laptop draws 0.6 A of current over 1 hour. How much charge was delivered to the laptop?

0.6 A

36 A

2160 C

### D

3600 C

Tags: Energy & Work | Quantitative Skills |

47

### Q:

A person exerts a force of 10 N onto a box at an angle of 60° from the horizontal. The box is pushed a distance of 2 m over the course of 5 seconds. How much power was exerted?

2 W

3.4 W

7 W

### D

12.5 W

Tags: Energy & Work | Quantitative Skills |

48

### Q:

Two ornaments are hanging from the ceiling, attached by springs with the same spring constant. Ball A masses 3kg and ball B masses 6kg. What is the tension in the spring from ball A?

10 N

30 N

40 N

### D

The answer cannot be determined from the given information.

Tags: Energy & Work | Quantitative Skills |

49

### Q:

How much work is done during the launch of a 5 kg projectile if it accelerates from rest at 105 m/s2 to a speed of 900 m/s?

2250 J

4 x 105 J

8 x 105 J

### D

2 x 106 J

Tags: Energy & Work | Quantitative Skills |

50

### Q:

How much energy needs to be added to 2 L of water to heat it from 20 °C to 100 °C? (Note: the specific heat capacity of water is 4.184 J/g*K)

669 J

6.4 x 105 J

6.69 x 105 J

### D

2.95 x 106 J

Tags: Energy & Work | Fluids | Quantitative Skills |

51

### Q:

How much work in Joules is done when a balloon expands from a volume of 2 L to a volume of 5 L against a constant pressure of 12 atm? Note: assume 1 L·atm = 100 J.

-3600 J

400 J

3600 J

### D

6000 J

Tags: Energy & Work | Gases | Quantitative Skills |

52

### Q:

Which of the following expressions does not have units equivalent to power?

### A

Current x Voltage

### B

Current2 x Resistance

### C

(Pressure x Volume)/time

### D

Δmomentum

Tags: Energy & Work |

53

### Q:

A block rests atop a frictionless incline at a height of 5 m. The incline angle is 18°. If the angle of the incline is increased to 56°, which of the following is true regarding the kinetic energy of the block when it reaches the bottom of the incline?

### A

The kinetic energy at 56° is less than at 18°.

### B

The kinetic energy at 56° is equal to the kinetic energy at 18°.

### C

The kinetic energy at 56° is greater than than at 18°.

### D

The answer cannot be determined from the given information.

Tags: Energy & Work |

54

### Q:

Which of the following expressions describes the work done by air resistance on a falling object between the time when it reaches its terminal velocity and the time when it impacts the ground?

mgh

### B

m(gh - (1/2)vterminal2)

√2gh

### D

(1/2)vterminal2

Tags: Forces | Energy & Work | Quantitative Skills |

55

### Q:

How much work is done by air resistance for a 10kg object moving at its terminal velocity from a height of 1000 m to 0 m?

0 J

√1000 J

105 J

### D

The answer cannot be determined from the given information.

Tags: Energy & Work | Quantitative Skills |

56

### Q:

Which of the following describes the energy conversion process involved in a person walking?

### A

kinetic to chemcial to heat

### B

chemical to heat to kinetic

### C

heat to chemical to kinetic

### D

chemical to kinetic to heat

Tags: Energy & Work |

57

### Q:

A 2kg projectile is shot at 60° to the horizontal with a velocity of 16 m/s. At the peak of its arc, what is its total kinetic energy? Neglect air resistance.

8 J

8√3 J

64 J

### D

16√3 J

Tags: Kinematics | Energy & Work | Quantitative Skills |

58

### Q:

The Stefan-Boltzmann law states that the power emitted per unit surface area of a black body can be written as j = kT4 where k is a constant and T is the absolute temperature in K. If a black body has its temperature increased from 25 °C to 330 °C, how much more power does it emit per unit surface area?

16 times more

305 times more

13 times more

### D

134 times more

Tags: Energy & Work | Quantitative Skills |

59

### Q:

A horizontal rocket is attached to a stationary car and begins to propel it forward. The rocket applies 10,000 N of force for 100 m of its total journey. Assuming no other propulsion is used for the car and its wheels are frictionless, how much work does the air do on the car over the course of its total journey?

0 J

10 J

106 J

### D

The answer cannot be determined with the given information.

Tags: Energy & Work | Quantitative Skills |

60

### Q:

An electric heater draws 12 A of current from a 120 V outlet for 90 minutes. If the cost of electricity is 15 cents per kW-hour, how much did it cost to run the heater for the 90 minutes?

13.5 cents

20.3 cents

21.6 cents

### D

32.4 cents

Tags: Energy & Work | Quantitative Skills |

61

### Q:

A 0.5kg projectile is launched 30° to the horizontal at 40 m/s. What is its total kinetic energy at the highest point of its path? Assume air resistance is negligible.

8.7 J

35 J

300 J

### D

1200 J

Tags: Kinematics | Energy & Work | Quantitative Skills |

62

### Q:

Assuming three identical blocks are released from the same height on frictionless inclines of differing angles, which block will be traveling fastest when it reaches the bottom?

### D

All blocks will be traveling at the same speed when they reach the bottom.

Tags: Kinematics | Energy & Work |

63

### Q:

A student is experimenting with a spring and wants to launch an object attached to the spring at 10 m/s. The spring is compressed and the object, with a mass of 1 kg, is placed at the end of the spring for launch. If the spring constant is 2500 N/m, how much does the spring need to be compressed to launch the object at the desired velocity?

0.2 cm

5 cm

20 cm

### D

25 cm

Tags: Energy & Work | Quantitative Skills |

64

### Q:

In which of the following situations is work not done?

### A

A chair is lifted vertically

### B

A bookcase is slid across carpeting

### C

A table is dropped onto the ground

### D

A stack of books is carried at waist level across a room

Tags: Energy & Work |

65

### Q:

A cart is moving toward a hill that is 50 m tall. The cart coasts up the hill but does not reach the top, missing the peak by only a few meters. After rolling back down, the driver doubles the weight of the cart in an attempt to double the momentum and make it over the hill. Which of the following is the most likely result of this strategy, assuming the same velocity is used as in the first attempt? Note: neglect friction and air resistance.

### A

The cart will reach the top but not make it over the hill

### B

The cart will reach the top and make it over the hill

### C

The cart will reach the same spot it reached before

### D

The cart will not reach as far as it reached before

Tags: Energy & Work |

66

### Q:

An object in space masses 10,000 kg and accelerates from a velocity of 1500 m/s to 3500 m/s over the course of 50 seconds. How much work was done to accelerate the object?

4 x 105 J

5 x 1010 J

1.25 x 105 J

### D

2 x 109 J

Tags: Kinematics | Energy & Work | Quantitative Skills |

67

### Q:

A toy car of mass 1 kg is pressed against a spring with k=100 N/m. The spring is compressed 20cm. At what velocity would the toy car be released from the spring?

4 m/s

√5 m/s

2 m/s

### D

√10 m/s

Tags: Energy & Work | Quantitative Skills |

68

### Q:

The gravitational potential energy of the moon with respect to the Earth is X. If the distance between the moon and Earth doubles, which of the following reflects the new gravitational potential energy?

2X

4X

X/2

### D

X/4

Tags: Energy & Work | Quantitative Skills |

69

### Q:

How much energy is required to run a 50 W motor for 3 hours?

50 kJ

150 kJ

360 kJ

### D

540 kJ

Tags: Energy & Work | Quantitative Skills |

70

### Q:

A spring with a k constant of 5 N/m is stretched 2 m from its equilibrium position by force F. Assume that this force continues to be applied as the spring is compressed to 2 m from its equilibrium position. How much work is performed by the force on the spring system?

0 J

20 J

25 J

### D

40 J

Tags: Forces | Energy & Work | Quantitative Skills |

71

### Q:

A mass is lifted from ground level to a height X and then to a height Y. It takes half the work to bring the mass from ground level to a height X than from point X to point Y. Which of the following is true?

Y = 2X

Y = 3X

Y = X/2

### D

Y = X/3

Tags: Energy & Work | Quantitative Skills |

72

### Q:

The graph of a capacitor in a circuit discharging is most similar to which of the following graphs?

### A

A graph of velocity vs time of a racecar decellerating at a constant rate

### B

A graph of displacement vs time of a runner who makes one revolution around a circular track

### C

A graph of power vs current in a circuit with constant voltage

### D

Potential energy vs time of a spring which is released from a stretched position and returns to a state of zero displacement

Tags: Energy & Work | Circuits |

73

### Q:

A block of mass m rests atop an incline at an angle of θ and with a coefficient of static friction of μ. At the current angle, the block slides down the incline when released. Which of the following would help prevent the block from sliding down the incline when released?

I. Decreasing θ
II. Increasing m
III. Decreasing μ

I only

II and III only

I and II only

### D

I and III only

Tags: Forces | Energy & Work |

74

### Q:

An object with mass M rests on a flat surface and has a coefficient of static friction of 0.2 and kinetic friction of 0.1. How much work is applied to move this object a distance D from rest if the object does not accelerate throughout motion?

0.15 x gD

0.1 x MD

0.2 x MgD

### D

0.1 x MgD

Tags: Energy & Work | Quantitative Skills |

75

### Q:

Two dirt paths lead up a hill, with Path A being 100 meters to the top of the hill, and Path B being 50 meters to the top. Compared to Path B, what is the average force exerted if you take Path A?

### A

The same as Path B

One half as much

Twice as much

### D

Four times as much

Tags: Forces | Energy & Work |

76

### Q:

Two balls, with one being twice as heavy as the other, are dropped to the ground from the top of a building. Which of the following best describes the kinetic energy of the heavier ball just before it hits the ground?

### A

It has half the kinetic energy as the lighter one

### B

It has the same kinetic energy as the lighter one

### C

It has twice the kinetic energy as the lighter one

### D

It has four times the kinetic energy as the lighter one

Tags: Energy & Work |

77

### Q:

A tennis ball is launched straight up into the air from a tennis ball launcher. Compared to the time it takes the ball to return from the top of its arc to the original position (t2), which of the following correctly describes the time (t1) it takes for the ball to reach the top of its arc? Assume air resistance.

### A

t1 is larger than t2

### B

t1 is smaller than t2

### C

t1 is equal to t2

### D

Neither t1 or t2 can be determined, due to a lack of information

Tags: Forces | Energy & Work |

78

### Q:

A box sits atop a frictionless ramp and then from rest, slides down it, achieving some speed at the very bottom (before it hits the floor). For that same box to achieve a speed (at the bottom of the ramp) twice as fast as the original, how much taller should a new ramp be?

### A

The new ramp should be the same height as the original, but with a more gradual slope

### B

The new ramp should be twice as high as the original

### C

The new ramp should be three times higher than the original

### D

The new ramp should be four times higher than the original

Tags: Kinematics | Energy & Work |

79

### Q:

An ideal spring-loaded gun fires a plastic ball straight up into the air, reaching the maximum height possible, due to the spring being fully compressed. Assuming no friction, if the spring were only compressed half as far, what would be the height of the plastic ball compared to the original?

Twice as high

Same height

Half as high

### D

One fourth as high

Tags: Kinematics | Energy & Work |

80

### Q:

How does the work required to accelerate a car from 0 to 50 ft/sec (w1) compare to the work required to accelerate that same car from 50 ft/sec to 100 ft/sec (w2)?

w1 = w2

w1 > w2

w1 < w2

### D

w1 and w2 cannot be determined from the given information

Tags: Energy & Work |

81

### Q:

An electron moving with a velocity of 500 m/s in the x-direction enters a region filled with a constant magnetic field (B), which has a magnitude of 0.25 teslas and points into the page. The constant field region is 5 m long and 4 m wide and the electron enters 0.5 m from the top of the region. What is the magnitude of the electron's velocity when it leaves the region?

125 m/s

250 m/s

500 m/s

### D

1,000 m/s

Tags: Magnetism | Energy & Work |

82

### Q:

A simple pendulum consists of mass m and length L. If the mass and pendulum length are doubled, the period will:

### A

Increase by a factor of 1.4

### B

Increase by a factor of 2

### C

Decrease by a factor of 1.4

### D

Decrease by a factor of 4

Tags: Quantitative Skills | Energy & Work | Periodic Motion |

83

### Q:

In a closed system with constant temperature, pressure can be plotted against volume in a PV diagram. Given this, which of the following is NOT true?

### A

The amount of energy expended by the system can be estimated by an area on the graph.

### B

The relationship between pressure and volume would always be linearly decreasing.

### C

The change in internal energy is equal to 0.

### D

An appropriate example that can be plotted in this PV diagram is an ideal gas in a container (in a constant-temperature environment) which is allowed to expand slowly.

Tags: Energy & Work | Miscellaneous General Chemistry | Quantitative Skills | Thermochemistry |

84

### Q:

An elevator is descending down an elevator shaft with constant speed. The elevator is supported by a single cable. Assuming the only forces at play are the tension in the cable and the force of gravity, then:

### A

the magnitude of the work done by the tension force is larger than the magnitude of the work done by gravity.

### B

the magnitude of the work done by the tension force is smaller than the magnitude of the work done by gravity.

### C

the net work done by the two forces is zero.

### D

the work done by the tension force is zero.

Tags: Forces | Energy & Work |

85

### Q:

At a hydroelectric plant, a falling fluid turns a turbine. The moving turbine is used to run electric generators. Given this scenario, which of the following is true?

### A

The magnitude of the electrical energy produced is equal to the magnitude of the gravitational potential energy released by the falling fluid.

### B

The magnitude of the electrical energy produced is less than the magnitude of the gravitational potential energy released by the falling fluid.

### C

The magnitude of the electrical energy produced is greater than the magnitude of the gravitational potential energy released by the falling fluid.

### D

The answer cannot be determined from the given information.

Tags: Energy & Work | Fluids |

86

### Q:

A pendulum that exhibits periodic motion:

### A

will have zero potential energy at its peak height.

### B

will have zero kinetic energy at its peak height.

### C

will have zero velocity when its displacement is minimized.

### D

will move faster as its distance from the equilibrium position increases.

Tags: Energy & Work | Periodic Motion |

87

### Q:

How much work is performed in lifting a 10kg object 5 meters in the air at constant speed in 2.5 seconds?

0 J

50 J

500 J

### D

1250 J

Tags: Energy & Work |

88

### Q:

Heat is applied to an object by placing it near a large fire. This mechanism of heat transfer is referred to as:

conduction

construction

### D

convection

Tags: Energy & Work |

89

### Q:

Which of the following is NOT a state function?

pressure

work

temperature

### D

volume

Tags: Energy & Work |

90

### Q:

An individual pushes a 1kg apple 2 meters along a surface with friction. Which of the following holds true:

### A

the force of pushing is nonconservative.

### B

potential energy at the end of the experiment is nonzero.

### C

work must be performed against gravitational forces.

### D

work performed is less in this experiment than if the surface were frictionless.

Tags: Energy & Work |

91

### Q:

Two objects with mass X and Y, respectively, are a distance R apart with a gravitational potential energy of P. If the distance between these two objects quadruples, the new gravitational potential energy will be:

1/16 P

1/4 P

4P

### D

16P

Tags: Energy & Work |

92

### Q:

A bright lamp heats the object which rests below it. This method of heat transfer can be described as:

convection.

conduction.

### D

supervention.

Tags: Energy & Work |

93

### Q:

A 40W lightbulb is lit for 10 minutes, requiring a certain amount of energy. If this energy were instead used to raise a 1kg mass, how high would the mass be raised (assuming gravitational force of 10m/s2)?

240 m

1 km

2.4 km

### D

4 km

Tags: Energy & Work |

94

### Q:

Spring A has double the spring constant of spring B. Spring B is stretched to double the displacement length as spring A. What is the ratio of the spring potential energy of spring B to spring A?

0.5

1

2

### D

4

Tags: Energy & Work |

95

### Q:

The Heisenberg uncertainty principle states that there is a limit to measuring the precision of which properties of quantum particles?

I. momentum
II. diameter
III. position

I and II only

II and III only

I and III only

### D

I, II and III

Tags: Energy & Work |

96

### Q:

A specific machine operates mainly via the use of a lever. It is measured that from an input force of 10 N, and output force of 40 N is produced via this lever mechanism. Which of the following is the mechanical advantage of this system?

0

0.25

4

### D

30

Tags: Energy & Work |

97

### Q:

Heat transfer through the movement of bulk amounts of molecules is referred to as:

convection.

conduction.

transduction.

### D

Tags: Energy & Work |

98

### Q:

How much approximate energy is required to operate a 10W machine for 1 week?

50 kJ

605 kJ

6,000 kJ

### D

720,000 kJ

Tags: Energy & Work |

99

### Q:

The distance between two planets suddenly increases 4-fold. What would be expected to happen to the gravitational potential energy?

stay the same

decrease to 1/2

decrease to 1/4

### D

decrease to 1/16

Tags: Energy & Work |

100

### Q:

Assuming Planck's constant is the 6 x 10-34 J*s, what is the energy of a photon with frequency 100 Hz?

2.5 x 10-32 J

2.5 x 10-36 J

6 x 10-32 J

### D

6 x 10-36 J

Tags: Energy & Work |

101

### Q:

A spring with a spring constant of 30000 N/m is stretched 10 mm from equilibrium. How much elastic potential energy is stored in the spring?

1.5 N/m2

15 N/m2

150 N/m2

### D

1500 N/m2

Tags: Energy & Work |

102

### Q:

A 100kg object is placed at the top of an inclined plane which has an angle of 45 degrees. The length of the plane is 7 meters. If the object rolls to the bottom of the plane from rest, what is the approximate velocity the object would achieve at the bottom of the plane? Assume a gravitational acceleration of 10 m/s2

4 m/s

6 m/s

8 m/s

### D

10 m/s

Tags: Kinematics | Energy & Work |

103

### Q:

Assuming that there is no air resistance, which of the following masses will have the greatest velocity right before striking the ground?

### A

a 5 kg ball dropped from 20 m.

### B

a 7 kg ball dropped from 10 m.

### C

a 10 kg ball dropped from 5 m

### D

a 100 kg ball dropped from 2 m.

Tags: Energy & Work |

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