Waec Physics Past Questions and Answers

Question 21:

• WAEC 1988

When three coplanar and non-parallel forces are in equilibrium,
I. they can be represented in magnitude and direction by the three sides of a triangle taken in order.
II. their lines of action meet at a point.
III. the magnitude of anyone equals the magnitude of the resultant of the other two.
IV. any one force is the equilibrant of the other two.Which of the following statements above are correct?

A. I & II only
B. II & III only
C. II, III & IV only
D. I, II, III & IV
E. I, III & IV only

Question 22:

• WAEC 1988

A ball of mass 0.5kg moving at 10ms^-1 collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.

A. 0.2ms^-1
B. 0.5ms^-1
C. 5.0ms^-1
D. 10.0ms^-1
E. 20.0ms^-1

Question 23:

• WAEC 1988

A body is projected into space with an initial velocity V₀ at an angle, θ to the horizontal. Which of the following statements is/are correct about its motion?
I. The total time of flight is (V₀ Cosθ)/g.
II. The maximum height is (V₀ Sin 2θ)/2g.
III. The range is (V₀² Cos²Î¸)/g.

A. I & II only
B. I & III only
C. II & III only
D. II only
E. III only

Question 24:

• WAEC 1988

A catapult is used to project a stone. Which of the following energy conversions takes place as the stone is released?

A. The kinetic energy of the stone is converted into gravitational potential energy
B. The gravitational potential energy of the catapult is converted into kinetic energy of the stone
C. The gravitational potential energy is converted into elastic potential energy
D. The elastic potential energy of the catapult is converted into gravitational potential energy of the stone
E. None of the above

Question 25:

• WAEC 1988

A ball is thrown vertically upwards from the ground with an initial velocity of 50ms^-1. What is the total time spent by the ball in the air? (g = 10ms^-2)

A. 2.5s
B. 5.0s
C. 10.0s
D. 15.0s
E. 20.0s