(a) Work, Energy and Power - Jamb Physics Past Questions and Answers

Question 16:

• JAMB 1987

A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms^-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms^-1]

A. 40%
B. 35%
C. 20%
D. 15%

Question 17:

• JAMB 1987

fig above represents the main sequence of energy conversion at kainji dam. what is the efficiency of the system?

A. Q1/Q2
B. E/Q1
C. E/(Q1-Q2)
D. E/(Q1-Q2)

Question 18:

• JAMB 1988

How long will it take a 60kg man to climb a height of 22m if he expended energy at a rate of 0.25kW. [g = ms^-2]

A. 5.3s
B. 34.5s
C. 41.6s
D. 52.8s

Question 19:

• JAMB 1988

A dynamo primarily combines

A. Mechanical energy into electrical energy
B. Electrical energy into kinetic energy
C. Potential energy into kinetic energy
D. Kinetic energy into potential energy

Question 20:

• JAMB 1990

To keep a vehicle moving at a constant speed v, requires power P, from the engine. The force provided by the engine is

A. \(\frac{p}{v}\)
B. \(\frac{1}{2}\) v
C. Pv
D. \(\frac{p}{v^2}\) v