Question 1

How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?

Accepted Answer

A) 0.22 kJ 
B) 0.20 kJ 
C) 0.24 kJ 
D) 0.27 kJ 
E) 0.31 kJ 
A) 0.22 kJ 
B) 0.20 kJ 
C) 0.24 kJ 
D) 0.27 kJ 
E) 0.31 kJ B

Question 2

A 4.0-kg block is lowered down a 37$\degree$ incline a distance of 5.0 m from point A to point B. A horizontal force (F = 10 N) is applied to the block between A and B as shown in the figure. The kinetic energy of the block at A is 10 J and at B it is 20 J. How much work is done on the block by the force of friction between A and B?

Accepted Answer

A) (-58 J) 
B) (-53 J) 
C) (-68 J) 
D) (-63 J) 
E) (-47 J) 
A) (-58 J) 
B) (-53 J) 
C) (-68 J) 
D) (-63 J) 
E) (-47 J) C

Question 3

Sally, who weighs 450 N, stands on a skate board while Roger pushes it forward 13.0 m at constant velocity on a level straight street. He applies a constant 100 N force.

Accepted Answer

A) The work Roger does on the skateboard is 0 J. 
B) The work Roger does on the skateboard is 1300 J. 
C) The work Sally does on the skateboard is 1300 J. 
D) The work Sally does on the skateboard is 5850 J. 
E) The work Roger does on the skateboard is 5850 J. 
A) The work Roger does on the skateboard is 0 J. 
B) The work Roger does on the skateboard is 1300 J. 
C) The work Sally does on the skateboard is 1300 J. 
D) The work Sally does on the skateboard is 5850 J. 
E) The work Roger does on the skateboard is 5850 J. B

Question 4

A 2.0-kg block sliding on a frictionless horizontal surface is attached to one end of a horizontal spring (k = 600 N/m) which has its other end fixed. The speed of the block when the spring is extended 20 cm is equal to 3.0 m/s. What is the maximum speed of this block as it oscillates?

Accepted Answer

A) 4.6 m/s 
B) 5.3 m/s 
C) 5.7 m/s 
D) 4.9 m/s 
E) 3.5 m/s 
A) 4.6 m/s 
B) 5.3 m/s 
C) 5.7 m/s 
D) 4.9 m/s 
E) 3.5 m/s

Question 5

After a skydiver reaches terminal velocity:

Accepted Answer

A) the force of gravity no longer performs work on the skydiver. 
B) work performed by the force of gravity is converted into gravitational potential energy. 
C) gravitational potential energy is no longer available to the system of the skydiver plus the Earth. 
D) gravitational potential energy is converted into thermal energy. 
E) thermal energy is converted into gravitational potential energy. 
A) the force of gravity no longer performs work on the skydiver. 
B) work performed by the force of gravity is converted into gravitational potential energy. 
C) gravitational potential energy is no longer available to the system of the skydiver plus the Earth. 
D) gravitational potential energy is converted into thermal energy. 
E) thermal energy is converted into gravitational potential energy.

Question 6

Equal amounts of work are performed on two bodies, A and B, initially at rest, and of masses m and 2m respectively. The relation between their speeds immediately after the work has been done on them is:

Accepted Answer

A) vA = $\sqrt{2}$ vB. 
B) vA = 2vB. 
C) vA = vB. 
D) vB = $\sqrt{2}$ vA. 
E) vB = 2vA. 
A) vA = $\sqrt{2}$ vB. 
B) vA = 2vB. 
C) vA = vB. 
D) vB = $\sqrt{2}$ vA. 
E) vB = 2vA.

Question 7

An object moving along the x axis is acted upon by a force Fx that varies with position as shown. How much work is done by this force as the object moves from x = 2 m to x = 8 m?

Accepted Answer

A) (-10 J) 
B) +10 J 
C) +30 J 
D) (-30 J) 
E) +40 J 
A) (-10 J) 
B) +10 J 
C) +30 J 
D) (-30 J) 
E) +40 J

Question 8

A 3.0-kg block is dragged over a rough horizontal surface by a constant force of 16 N acting at an angle of 37$\degree$ above the horizontal as shown. The speed of the block increases from 4.0 m/s to 6.0 m/s in a displacement of 5.0 m. What work was done by the friction force during this displacement?

Accepted Answer

A) (-34 J) 
B) (-64 J) 
C) (-30 J) 
D) (-94 J) 
E) +64 J 
A) (-34 J) 
B) (-64 J) 
C) (-30 J) 
D) (-94 J) 
E) +64 J

Question 9

A block slides on a rough horizontal surface from point A to point B. A force (magnitude P = 2.0 N) acts on the block between A and B, as shown. Points A and B are 1.5 m apart. If the kinetic energies of the block at A and B are 5.0 J and 4.0 J, respectively, how much work is done on the block by the force of friction as the block moves from A to B?

Accepted Answer

A) (-3.3 J) 
B) +1.3 J 
C) +3.3 J 
D) (-1.3 J) 
E) +4.6 J 
A) (-3.3 J) 
B) +1.3 J 
C) +3.3 J 
D) (-1.3 J) 
E) +4.6 J

Question 10

While running, a person dissipates about 0.6 J of mechanical energy per step per kilogram of body mass. If a 60-kg person runs with a power of 70 Watts during a race, how fast is the person running? Assume a running step is 1.5 m long.

Accepted Answer

The answer of While running, a person dissipates about 0.6...

Question 11

The only force acting on a 2.0-kg body moving along the x axis is given by Fx = (2.0x) N, where x is in m. If the velocity of the object at x = 0 is +3.0 m/s, how fast is it moving at x = 2.0 m?

Accepted Answer

A) 4.2 m/s 
B) 3.6 m/s 
C) 5.0 m/s 
D) 5.8 m/s 
E) 2.8 m/s 
A) 4.2 m/s 
B) 3.6 m/s 
C) 5.0 m/s 
D) 5.8 m/s 
E) 2.8 m/s

Question 12

The horizontal surface on which the block slides is frictionless. The speed of the block before it touches the spring is 6.0 m/s. How fast is the block moving at the instant the spring has been compressed 15 cm? k = 2.0 kN/m

Accepted Answer

A) 3.7 m/s 
B) 4.4 m/s 
C) 4.9 m/s 
D) 5.4 m/s 
E) 14 m/s 
A) 3.7 m/s 
B) 4.4 m/s 
C) 4.9 m/s 
D) 5.4 m/s 
E) 14 m/s

Question 13

The equation below is the solution to a physics problem: $\frac{1}{2}(2.30 \mathrm{~kg})\left(3.90 \frac{\mathrm{~m}}{\mathrm{~s}}\right)^{2}=\frac{1}{2}(2.30 \mathrm{~kg})\left(2.33 \frac{\mathrm{~m}}{\mathrm{~s}}\right)^{2}+(2.30 \mathrm{~kg})\left(9.80 \frac{\mathrm{~m}}{\mathrm{~s}^{2}}\right)(1.00 \mathrm{~m}) \cos \left(60^{\circ}\right)$ .The most likely physical situation it describes is:

Accepted Answer

A) a 2.30 kg cart rolling up a 30$\degree$ incline. 
B) a 2.30 kg cart rolling down a 30$\degree$ incline. 
C) a 2.30 kg cart rolling up a 60$\degree$ incline. 
D) a 2.30 kg cart rolling down a 60$\degree$ incline. 
E) a 2.30 kg cart rolling down a 90$\degree$ incline. 
A) a 2.30 kg cart rolling up a 30$\degree$ incline. 
B) a 2.30 kg cart rolling down a 30$\degree$ incline. 
C) a 2.30 kg cart rolling up a 60$\degree$ incline. 
D) a 2.30 kg cart rolling down a 60$\degree$ incline. 
E) a 2.30 kg cart rolling down a 90$\degree$ incline.

Question 14

A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.5 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B?

Accepted Answer

A) 2.7 J 
B) 1.0 J 
C) 2.2 J 
D) 1.6 J 
E) 3.2 J 
A) 2.7 J 
B) 1.0 J 
C) 2.2 J 
D) 1.6 J 
E) 3.2 J

Question 15

A 30-kg child sitting 5.0 m from the centre of a merry-go-round has a constant speed of 5.0 m/s. While she remains seated in the same spot and travels in a circle, the work the seat performs on her in one complete rotation is:

Accepted Answer

A) 0 J. 
B) 150 J. 
C) 1500 J. 
D) 4700 J. 
E) 46 000 J. 
A) 0 J. 
B) 150 J. 
C) 1500 J. 
D) 4700 J. 
E) 46 000 J.

Question 16

Carts A and B have equal masses and travel equal distances D on side-by-side straight frictionless tracks while a constant force F acts on A and a constant force 2F acts on B. Both carts start from rest. The velocities $\overrightarrow{\mathbf{v}}$ A and $\overrightarrow{\mathbf{v}}$ B of the bodies at the end of distance D are related by:

Accepted Answer

A)  $\overrightarrow{\mathbf{v}}$ B = $\overrightarrow{\mathbf{v}}$ A . 
B)  $\overrightarrow{\mathbf{v}}$ B = $\sqrt{2}$
$\overrightarrow{\mathbf{v}}$ A. 
C)  $\overrightarrow{\mathbf{v}}$ B = 2 $\overrightarrow{\mathbf{v}}$ A. 
D)  $\overrightarrow{\mathbf{v}}$ B = 4 $\overrightarrow{\mathbf{v}}$ A. 
E)  $\overrightarrow{\mathbf{v}}$ A = 2 $\overrightarrow{\mathbf{v}}$ B. 
A)  $\overrightarrow{\mathbf{v}}$ B = $\overrightarrow{\mathbf{v}}$ A . 
B)  $\overrightarrow{\mathbf{v}}$ B = $\sqrt{2}$
$\overrightarrow{\mathbf{v}}$ A. 
C)  $\overrightarrow{\mathbf{v}}$ B = 2 $\overrightarrow{\mathbf{v}}$ A. 
D)  $\overrightarrow{\mathbf{v}}$ B = 4 $\overrightarrow{\mathbf{v}}$ A. 
E)  $\overrightarrow{\mathbf{v}}$ A = 2 $\overrightarrow{\mathbf{v}}$ B.

Question 17

The same constant force is used to accelerate two carts of the same mass, initially at rest, on horizontal frictionless tracks. The force is applied to cart A for twice as long a time as it is applied to cart B. The work the force does on A is WA; that on B is WB. Which statement is correct?

Accepted Answer

A) WA = WB. 
B) WA = $\sqrt{2}$ WB. 
C) WA = 2 WB. 
D) WA = 4 WB. 
E) WB = 2 WA. 
A) WA = WB. 
B) WA = $\sqrt{2}$ WB. 
C) WA = 2 WB. 
D) WA = 4 WB. 
E) WB = 2 WA.

Question 18

Two cannonballs are dropped from a second floor physics lab at height h above the ground. Ball B has four times the mass of ball A. When the balls pass the bottom of a first floor window at height $\frac{h}{4}$ above the ground, the relation between their kinetic energies, KA and KB, is:

Accepted Answer

A) KA = 4KB. 
B) KA = 2KB. 
C) KA = KB. 
D) KB = 2KA. 
E) KB = 4KA. 
A) KA = 4KB. 
B) KA = 2KB. 
C) KA = KB. 
D) KB = 2KA. 
E) KB = 4KA.

Question 19

A body moving along the x axis is acted upon by a force Fx that varies with x as shown. How much work is done by this force as the object moves from x = 1 m to x = 8 m?

Accepted Answer

A) (-2 J) 
B) (-18 J) 
C) (-10 J) 
D) (-26 J) 
E) +18 J 
A) (-2 J) 
B) (-18 J) 
C) (-10 J) 
D) (-26 J) 
E) +18 J

Question 20

A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate, she would reach the summit in ____ seconds.

Accepted Answer

A) 1 
B) 460 
C) 500 
D) 1000 
E) 35 000 
A) 1 
B) 460 
C) 500 
D) 1000 
E) 35 000

How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?

Sally, who weighs 450 N, stands on a skate board while Roger pushes it forward 13.0 m at constant velocity on a level straight street. He applies a constant 100 N force.

A 2.0-kg block sliding on a frictionless horizontal surface is attached to one end of a horizontal spring (k = 600 N/m) which has its other end fixed. The speed of the block when the spring is extended 20 cm is equal to 3.0 m/s. What is the maximum speed of this block as it oscillates?

After a skydiver reaches terminal velocity:

Equal amounts of work are performed on two bodies, A and B, initially at rest, and of masses m and 2m respectively. The relation between their speeds immediately after the work has been done on them is:

An object moving along the x axis is acted upon by a force Fx that varies with position as shown. How much work is done by this force as the object moves from x = 2 m to x = 8 m?

While running, a person dissipates about 0.6 J of mechanical energy per step per kilogram of body mass. If a 60-kg person runs with a power of 70 Watts during a race, how fast is the person running? Assume a running step is 1.5 m long.

The only force acting on a 2.0-kg body moving along the x axis is given by Fx = (2.0x) N, where x is in m. If the velocity of the object at x = 0 is +3.0 m/s, how fast is it moving at x = 2.0 m?

The horizontal surface on which the block slides is frictionless. The speed of the block before it touches the spring is 6.0 m/s. How fast is the block moving at the instant the spring has been compressed 15 cm? k = 2.0 kN/m

A 30-kg child sitting 5.0 m from the centre of a merry-go-round has a constant speed of 5.0 m/s. While she remains seated in the same spot and travels in a circle, the work the seat performs on her in one complete rotation is:

The same constant force is used to accelerate two carts of the same mass, initially at rest, on horizontal frictionless tracks. The force is applied to cart A for twice as long a time as it is applied to cart B. The work the force does on A is WA; that on B is WB. Which statement is correct?

Two cannonballs are dropped from a second floor physics lab at height h above the ground. Ball B has four times the mass of ball A. When the balls pass the bottom of a first floor window at height $\frac{h}{4}$ above the ground, the relation between their kinetic energies, KA and KB, is:

A body moving along the x axis is acted upon by a force Fx that varies with x as shown. How much work is done by this force as the object moves from x = 1 m to x = 8 m?

A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate, she would reach the summit in ____ seconds.

Physics and Measurement

Motion in One Dimension

Motion in Two Dimensions

Forces and Newtons Laws

Further Applications of Newtons Laws

Conservation of Energy

Linear Momentum and Collisions

Rotational Motion

Energy and Momentum in Rotating Systems

Gravity

Special Relativity

Fluid Statics

Fluid Dynamics

Solids

Oscillatory Motion

Wave Motion

Superposition and Interference

Heat and Temperature

Energy Transfer Processes and Thermodynamics

The Kinetic Theory of Gases

The Second Law of Thermodynamics, Heat Engines and Entropy

Filters

Exam 6: Work, Force and Energy

How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?

Sally, who weighs 450 N, stands on a skate board while Roger pushes it forward 13.0 m at constant velocity on a level straight street. He applies a constant 100 N force.

A 2.0-kg block sliding on a frictionless horizontal surface is attached to one end of a horizontal spring (k = 600 N/m) which has its other end fixed. The speed of the block when the spring is extended 20 cm is equal to 3.0 m/s. What is the maximum speed of this block as it oscillates?

After a skydiver reaches terminal velocity:

Equal amounts of work are performed on two bodies, A and B, initially at rest, and of masses m and 2m respectively. The relation between their speeds immediately after the work has been done on them is:

An object moving along the x axis is acted upon by a force Fx that varies with position as shown. How much work is done by this force as the object moves from x = 2 m to x = 8 m?

While running, a person dissipates about 0.6 J of mechanical energy per step per kilogram of body mass. If a 60-kg person runs with a power of 70 Watts during a race, how fast is the person running? Assume a running step is 1.5 m long.

The only force acting on a 2.0-kg body moving along the x axis is given by Fx = (2.0x) N, where x is in m. If the velocity of the object at x = 0 is +3.0 m/s, how fast is it moving at x = 2.0 m?

The horizontal surface on which the block slides is frictionless. The speed of the block before it touches the spring is 6.0 m/s. How fast is the block moving at the instant the spring has been compressed 15 cm? k = 2.0 kN/m

A 30-kg child sitting 5.0 m from the centre of a merry-go-round has a constant speed of 5.0 m/s. While she remains seated in the same spot and travels in a circle, the work the seat performs on her in one complete rotation is:

The same constant force is used to accelerate two carts of the same mass, initially at rest, on horizontal frictionless tracks. The force is applied to cart A for twice as long a time as it is applied to cart B. The work the force does on A is WA; that on B is WB. Which statement is correct?

Two cannonballs are dropped from a second floor physics lab at height h above the ground. Ball B has four times the mass of ball A. When the balls pass the bottom of a first floor window at height h4\frac{h}{4}4h​ above the ground, the relation between their kinetic energies, KA and KB, is:

A body moving along the x axis is acted upon by a force Fx that varies with x as shown. How much work is done by this force as the object moves from x = 1 m to x = 8 m?

A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate, she would reach the summit in ____ seconds.

Physics and Measurement

Motion in One Dimension

Motion in Two Dimensions

Forces and Newtons Laws

Further Applications of Newtons Laws

Conservation of Energy

Linear Momentum and Collisions

Rotational Motion

Energy and Momentum in Rotating Systems

Gravity

Special Relativity

Fluid Statics

Fluid Dynamics

Solids

Oscillatory Motion

Wave Motion

Superposition and Interference

Heat and Temperature

Energy Transfer Processes and Thermodynamics

The Kinetic Theory of Gases

The Second Law of Thermodynamics, Heat Engines and Entropy

Filters

Two cannonballs are dropped from a second floor physics lab at height h above the ground. Ball B has four times the mass of ball A. When the balls pass the bottom of a first floor window at height $\frac{h}{4}$ above the ground, the relation between their kinetic energies, KA and KB, is: