WorksheetsWorksheet 6 - Energy
Total questions: 19
Worksheet time: 19mins
1. A stone enters a deep pool at high speed. It slows down as it moves towards the bottom of the pool.
What is the energy transformation as the stone moves downwards through the water?
A. gravitational potential energy --> kinetic energy + thermal energy
B. gravitational potential energy --> kinetic energy --> thermal energy
C. kinetic energy + gravitational potential energy --> thermal energy
D. kinetic energy --> gravitational potential energy + thermal energy
Q2. A boy drops a ball from a height. Ignoring the effects of air resistance, the total energy is
A. greatest at point 1
B. greatest at point 2
C. greatest at point 3
D. the same at all three points
Q3. The diagram shows the side view of a roller coaster track. The car is released from position P.
Which of the following statements is/are true?
1. The total energy is the same at each of the three positions shown.
2. The kinetic energy of the car is greater at Q than at R.
3. The gravitational potential energy of the car is greater at R than at P.
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2 and 3
Q4. A lorry of total mass 15 000 kg takes sand to the top of a hill 50 m high, unloads all the sand and then returns to the bottom of the hill. The empty lorry has a mass of 10 000 kg.
The gravitational field strength g is 10 N/kg.
What is the difference between the final gravitational potential energy and the initial gravitational potential energy of the sand?
A. 250 000 J
B. 750 000 J
C. 2 500 000 J
D. 7 500 000 J
Q5. A ball of mass 0.3 kg is thrown at a speed of 20 m/s. What is its kinetic energy?
A. 3 J
B. 9 J
C. 36 J
D. 60 J
Q6. An arrow is shot vertically upward with an initial speed of 12 m/s.
What is the maximum height the arrow can reach? Take g = 10 N/kg.
A. 7.2 m
B. 72 m
C. 144 m
D. 172 m
Q7. A body of mass of 50 kg falls freely from a height of 20 m.
The gravitational field strength g is 10 N/kg.
What is the speed of the body when it hits the ground?
A. 10 m/s
B. 20 m/s
C. 200 m/s
D. 400 m/s
Q8. A roller-coaster train of mass 2000 kg is stationary at the top of its run. The train has gravitational potential energy of 1600 kJ. When released, it rolls down the track and reaches the bottom at a speed of 30 m/s.
How much energy is lost by the train as it travels down the run?
A. 700 kJ
B. 900 kJ
C. 1510 kJ
D. 2500 kJ
Q9. A ball is at rest at point X in a vacuum. The ball falls under gravity from X to Y to Z. Distances are shown on the diagram.
What is the ratio of KE of ball at Z to the KE of ball at Y?
2
2
22
4
Q10. Object P has a mass of 1.0 kg and is moving with a speed of 1.0 m/s. Object Q has a mass of 2.0 kg and is moving with a speed of 0.50 m/s.
How do the kinetic energies of P and Q compare?
A. The kinetic energy of P is one half the kinetic energy of Q.
B. The kinetic energy of P is the same as that of Q.
C. The kinetic energy of P is twice the kinetic energy of Q.
D. The kinetic energy of P is four times the kinetic energy of Q.
Q11. A mass M is hung from a spring. It is then pulled down slightly and allowed to vibrate vertically between P and Q.
Which row is correct?
P: kinetic, Q: kinetic
P: kinetic, Q: potential
P: potential, Q: kinetic
P: potential, Q: potential
Q12. An electric motor is used to lift a 5 N load through 3 m, as shown in the diagram.
The total amount of electrical energy used by the motor is 27 J.
How much energy is lost to surroundings?
A. 9 J
B. 12 J
C. 15 J
D. 27 J
Q13. An electric motor produces a force F to pull a trolley up a ramp. There is no friction or air resistance acting.
Which quantity is equal to the work done by the force F?
A. the acceleration of the trolley
B. the energy given to the trolley
C. the power of the motor
D. the weight of the trolley
Q14. A car moves from rest with uniform acceleration along a horizontal road.
After travelling a distance of 100 metres, it has kinetic energy equal to 200 000 J.
What resultant force is acting on the car?
A. 100 N
B. 1000 N
C. 2000 N
D. 20 000 N
Q 15. A 2 kg box slides from the top to the bottom of a ramp. Given that the speed of the box is 10 m/s at the bottom of the ramp.
Calculate the total amount of energy lost to the surroundings. Take g = 10 N/kg.
A. 20 J
B. 80 J
C. 100 J
D. 120 J
Q16. An 80 kg man walks up a flight of steps to reach a height of 4 m in 16 seconds.
Calculate the minimum power required by the man.
A. 20 W
B. 80 W
C. 200 W
D. 5120 W
Q17. An experiment is carried out to estimate the useful power output of a student running up some stairs, ignoring the work equation against friction.
What is not required for this experiment?
A. the time taken to run up the stairs
B. the total horizontal distance of the stairs
C. the total vertical height of the stairs
D. the weight of the student
Q18. 1. Some students climb a set of stairs at school, and each student is timed. Their weights and times are recorded in the table.
Which student develops the most power?
A
B
C
D
Q19. A box is pushed 10 m along a horizontal surface by a force of 8 N. The frictional force opposing the motion is 6 N.
How much of the work done is converted to thermal energy and kinetic energy?
A
B
C
D
