Question 1

An ideal spring requires 50 J to be compressed by 15 cm.The value of the spring constant of this spring is

Accepted Answer

A) 2222 N/m. 
B) 667 N/m. 
C) 4444 N/m. 
D) 5648 N/m. 
E) 1245 N/m. 
A) 2222 N/m. 
B) 667 N/m. 
C) 4444 N/m. 
D) 5648 N/m. 
E) 1245 N/m.

Question 2

A 20.0-kg object starts from rest and slides down an inclined plane.The change in its elevation is 2.50 m and its final speed is 5.00 m/sec.How much energy did the object lose due to friction as it slid down the plane?

Accepted Answer

A) 241 J 
B) 245 J 
C) 250 J 
D) 491 J 
A) 241 J 
B) 245 J 
C) 250 J 
D) 491 J

Question 3

A ball of mass 1.5 kg is shot horizontally from a building of height of 11 m with a velocity of 10 m/s.What is the kinetic energy of the ball when it hits the ground?

Accepted Answer

A) 23.2 J 
B) 9800 J 
C) 15.0 J 
D) 911 J 
E) 237 J 
A) 23.2 J 
B) 9800 J 
C) 15.0 J 
D) 911 J 
E) 237 J

Question 4

A 60% efficient engine is used to haul 200 kg steel beams up to the ninth floor.How much energy needs to be supplied to the engine to lift the beams from the second floor 20 m below?

Accepted Answer

A) 200 J 
B) 65,400 J 
C) 3920 J 
D) 14,540 J 
E) 6880 J 
A) 200 J 
B) 65,400 J 
C) 3920 J 
D) 14,540 J 
E) 6880 J

Question 5

A 5.0-kg crate is lifted straight up from the ground at a constant speed of 1.5 m/s to the back of a moving truck which is at a height of 5.0 m above the ground.What power is needed to accomplish this task?

Accepted Answer

A) 25 W 
B) 53 W 
C) 74 W 
D) 87 W 
E) 101 W 
A) 25 W 
B) 53 W 
C) 74 W 
D) 87 W 
E) 101 W

Question 6

A 15,000-kg train accelerates uniformly from 0 to 15 m/s when passing through a distance of 150 m.What is its kinetic energy when it is 75 m down the track?

Accepted Answer

A) 420 kJ 
B) 600 kJ 
C) 840 kJ 
D) 1200 kJ 
E) 1700 kJ 
A) 420 kJ 
B) 600 kJ 
C) 840 kJ 
D) 1200 kJ 
E) 1700 kJ

Question 7

A man of mass 60 kg runs up a flight of 60 steps in 40 seconds.If each step is 20 cm high,his power is

Accepted Answer

A) 240 W. 
B) 177 W. 
C) 134 W. 
D) 18 W. 
A) 240 W. 
B) 177 W. 
C) 134 W. 
D) 18 W.

Question 8

An engine with 75 kW of power can accelerate a car from rest to 20 m/s during 6.0 s.What is the mass of the car (ignore friction and air resistance)?

Accepted Answer

A) 1.25 F1F1F1S1F1F1F10 103 kg 
B) 2.25 F1F1F1S1F1F1F10 103 kg 
C) 3.25 F1F1F1S1F1F1F10 103 kg 
D) 2.65 F1F1F1S1F1F1F10 103 kg 
E) 1.85 F1F1F1S1F1F1F10 103 kg 
A) 1.25 F1F1F1S1F1F1F10 103 kg 
B) 2.25 F1F1F1S1F1F1F10 103 kg 
C) 3.25 F1F1F1S1F1F1F10 103 kg 
D) 2.65 F1F1F1S1F1F1F10 103 kg 
E) 1.85 F1F1F1S1F1F1F10 103 kg

Question 9

How much work is done on a 7.26-kg shot by the shot putter if he launches shot at 45.0S1U1P1$\circ$S1S1P0,and it lands 23.0 m from the launch point (ignore the height of the shot putter).

Accepted Answer

A) 396 J 
B) 579 J 
C) 792 J 
D) 819 J 
A) 396 J 
B) 579 J 
C) 792 J 
D) 819 J

Question 10

A constant force of 41.5 N,directed at 32.9F1F1F1S1F1F1F10 from horizontal,pulls a mass of 12.7 kg horizontally a distance of 3.33 m.Calculate the work done by the force.(in J).

Accepted Answer

A) 8.04 F1F1F1S1F1F1F10 101 
B) 9.09 F1F1F1S1F1F1F10 101 
C) 1.03 F1F1F1S1F1F1F10 102 
D) 1.16 F1F1F1S1F1F1F10 102 
E) 1.31 F1F1F1S1F1F1F10 102 
A) 8.04 F1F1F1S1F1F1F10 101 
B) 9.09 F1F1F1S1F1F1F10 101 
C) 1.03 F1F1F1S1F1F1F10 102 
D) 1.16 F1F1F1S1F1F1F10 102 
E) 1.31 F1F1F1S1F1F1F10 102

Exam 5: Kinetic Energy, work, and Power

An ideal spring requires 50 J to be compressed by 15 cm.The value of the spring constant of this spring is

A 20.0-kg object starts from rest and slides down an inclined plane.The change in its elevation is 2.50 m and its final speed is 5.00 m/sec.How much energy did the object lose due to friction as it slid down the plane?

A ball of mass 1.5 kg is shot horizontally from a building of height of 11 m with a velocity of 10 m/s.What is the kinetic energy of the ball when it hits the ground?

A 60% efficient engine is used to haul 200 kg steel beams up to the ninth floor.How much energy needs to be supplied to the engine to lift the beams from the second floor 20 m below?

A 5.0-kg crate is lifted straight up from the ground at a constant speed of 1.5 m/s to the back of a moving truck which is at a height of 5.0 m above the ground.What power is needed to accomplish this task?

A 15,000-kg train accelerates uniformly from 0 to 15 m/s when passing through a distance of 150 m.What is its kinetic energy when it is 75 m down the track?

A man of mass 60 kg runs up a flight of 60 steps in 40 seconds.If each step is 20 cm high,his power is

An engine with 75 kW of power can accelerate a car from rest to 20 m/s during 6.0 s.What is the mass of the car (ignore friction and air resistance)?

How much work is done on a 7.26-kg shot by the shot putter if he launches shot at 45.0 ∘\circ∘ ,and it lands 23.0 m from the launch point (ignore the height of the shot putter).

A constant force of 41.5 N,directed at 32.9 from horizontal,pulls a mass of 12.7 kg horizontally a distance of 3.33 m.Calculate the work done by the force.(in J).

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How much work is done on a 7.26-kg shot by the shot putter if he launches shot at 45.0^$\circ$,and it lands 23.0 m from the launch point (ignore the height of the shot putter).