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

Question 26:

• JAMB 1995

A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed

A. \(\frac{mv^2}{t}\)
B. \(\frac{mv^2}{2t}\)
C. \(\frac{mv}{t}\)
D. \(\frac{mv}{2t}\)

Question 27:

• JAMB 1995

The energy contained in a wire when it extended by 0.02m by a force 500 N is

A. 5J
B. 10J
C. 10³J
D. 10⁴

Question 28:

• JAMB 1995

A body of mass 40kg is being dragged along the floor by a rope inclined at 60 degrees to the horizontal. The frictional force between the box and the floor is 100N and the tension on the rope is 300N. How much work is done by dragging the box for a distance of 4m

A. 680J
B. 400J
C. 200J
D. 100J

Question 29:

• JAMB 1997

An object of mass 100g projected vertically upwards from the ground level has a velocity of 20ms^-1 at a height of 10m. calculate its initial kinetic energy at the ground level.[g = 10ms^-2, neglect air resistance]

A. 10 J
B. 20 J
C. 30 J
D. 50 J

Question 30:

• JAMB 1999

A car of mass 800kg attains a speed of 25m/s in 20 secs. The power developed in the engine is

A. 1 . 25 x 10⁴ W
B. 2 . 50 x 10⁴ W
C. 1 . 25 x 10⁶W
D. 2 . 50 x 10⁶ W