Question Number. 26. A block slides down a slope. Assuming there is no friction.

Option A. kinetic energy is gained at the same rate as potential energy is lost.

Option B. kinetic energy is gained at a greater rate than potential energy is lost.

Option C. potential energy is gained at a greater rate than kinetic energy is lost.

Correct Answer is. kinetic energy is gained at the same rate as potential energy is lost.

Explanation. KE gained = PE lost (at the same rate).

Question Number. 27. The English unit of mass is.

Option A. the Newton.

Option B. the kilogram.

Option C. the slug.

Correct Answer is. the slug.

Explanation. The British unit of mass is the Slug.

Question Number. 28. The SI unit of energy is the.

Option A. Watt (W).

Option B. Pascal (Pa).

Option C. Joule (J).

Correct Answer is. Joule (J).

Explanation. NIL.

Question Number. 29. A 4.5 kW electric motor is 90% efficient. How much energy does it use in 20 seconds?.

Option A. 90 kJ.

Option B. 2.25 kJ.

Option C. 100 kJ.

Correct Answer is. 100 kJ.

Explanation. NIL.

Question Number. 30. A pile driver of mass 1000 kg, hits a post 3 m below it. It moves the post 10 mm. Assuming gravity = 10 m/s, what is the kinetic energy of the pile driver?.

Option A. 30 kJ.

Option B. 45 kJ.

Option C. 90 kJ.

Correct Answer is. 30 kJ.

Explanation. NIL.

Question Number. 31. The SI unit for work is the.

Option A. Joule.

Option B. Watt.

Option C. horsepower.

Correct Answer is. Joule.

Explanation. NIL.

Question Number. 32. What work is done if a force of 100 N moves a body 15 metres?.

Option A. 1500 kJ.

Option B. 1.5 kJ.

Option C. 0.15 mJ.

Correct Answer is. 1.5 kJ.

Explanation. Work = force * distance 100N * 15m = 1500J, or 1.5kJ.

Question Number. 33. Power is the rate of doing work. It is measured in.

Option A. Joules * Seconds.

Option B. Joules/Seconds.

Option C. Watts/Seconds.

Correct Answer is. Joules/Seconds.

Explanation. Power = energy per second = Joules/second.

Question Number. 34. A block slides down a slope. Assuming there is no friction.

Option A. potential energy is gained at a greater rate than kinetic energy is lost.

Option B. kinetic energy is gained at the same rate as potential energy is lost.

Option C. kinetic energy is gained at a greater rate than potential energy is lost.

Correct Answer is. kinetic energy is gained at the same rate as potential energy is lost.

Explanation. KE gained = PE lost (at the same rate).

Option A. kinetic energy is gained at the same rate as potential energy is lost.

Option B. kinetic energy is gained at a greater rate than potential energy is lost.

Option C. potential energy is gained at a greater rate than kinetic energy is lost.

Correct Answer is. kinetic energy is gained at the same rate as potential energy is lost.

Explanation. KE gained = PE lost (at the same rate).

Question Number. 27. The English unit of mass is.

Option A. the Newton.

Option B. the kilogram.

Option C. the slug.

Correct Answer is. the slug.

Explanation. The British unit of mass is the Slug.

Question Number. 28. The SI unit of energy is the.

Option A. Watt (W).

Option B. Pascal (Pa).

Option C. Joule (J).

Correct Answer is. Joule (J).

Explanation. NIL.

Question Number. 29. A 4.5 kW electric motor is 90% efficient. How much energy does it use in 20 seconds?.

Option A. 90 kJ.

Option B. 2.25 kJ.

Option C. 100 kJ.

Correct Answer is. 100 kJ.

Explanation. NIL.

Question Number. 30. A pile driver of mass 1000 kg, hits a post 3 m below it. It moves the post 10 mm. Assuming gravity = 10 m/s, what is the kinetic energy of the pile driver?.

Option A. 30 kJ.

Option B. 45 kJ.

Option C. 90 kJ.

Correct Answer is. 30 kJ.

Explanation. NIL.

Question Number. 31. The SI unit for work is the.

Option A. Joule.

Option B. Watt.

Option C. horsepower.

Correct Answer is. Joule.

Explanation. NIL.

Question Number. 32. What work is done if a force of 100 N moves a body 15 metres?.

Option A. 1500 kJ.

Option B. 1.5 kJ.

Option C. 0.15 mJ.

Correct Answer is. 1.5 kJ.

Explanation. Work = force * distance 100N * 15m = 1500J, or 1.5kJ.

Question Number. 33. Power is the rate of doing work. It is measured in.

Option A. Joules * Seconds.

Option B. Joules/Seconds.

Option C. Watts/Seconds.

Correct Answer is. Joules/Seconds.

Explanation. Power = energy per second = Joules/second.

Question Number. 34. A block slides down a slope. Assuming there is no friction.

Option A. potential energy is gained at a greater rate than kinetic energy is lost.

Option B. kinetic energy is gained at the same rate as potential energy is lost.

Option C. kinetic energy is gained at a greater rate than potential energy is lost.

Correct Answer is. kinetic energy is gained at the same rate as potential energy is lost.

Explanation. KE gained = PE lost (at the same rate).

Page 2