# 1992 - WAEC Physics Past Questions & Answers - page 1

1
Which of the following is a scalar quantity?
A
Momentum
B
Acceleration
C
Displacement
D
Distance
CORRECT OPTION: d
2
The diagram above represents the trajectory of a projectile with an initial velocity U. Calculate the time taken to reach the maximum height. (Take g as acceleration due to gravity)
A
Usinθ/2g
B
2Usinθ/g
C
Ucosθ/g
D
2Ucosθ/g
CORRECT OPTION: e
3
What change in velocity would be produced on a body of mass 4kg if a constant force of 16 N acts on it for2 s?
A
0.5 ms-1
B
2.0ms-1
C
8.0 ms-1
D
32.0 ms-1
CORRECT OPTION: c
F =
m(v - u)/t; (v - u) =
Ft/m = 8.0
4
Which of the following statements about solid friction is/are correct? I. Friction depends on the nature of the surfaces in contact II. Friction depends on the area of contact III. Friction always acts in the direction of motion.
A
I only
B
II only
C
III only
D
I and II only
CORRECT OPTION: a
5
A body accelerates uniformly from rest at the rate of 3 ms-1 for 8 seconds. Calculate the distance covered by the body during the acceleration.
A
12m
B
24m
C
48m
D
72m
CORRECT OPTION: e
S = ut + 1/2at2 = 0 + 1/2 x 3 x 82
= 96m
6
Which of the following has the same unit as the moment of a force?
A
Force
B
Power
C
Work
D
Momentum
CORRECT OPTION: c
7
Solid weighs 0.040 N in air and 0.024 N when fully immersed in a liquid of density 800 kg m-3. What is the volume of the solid? (g = 1Oms2)
A
2.0 x 10-6m3
B
2.5x10-6m3
C
3.0x10-6m3
D
2.0x 10-5m3
CORRECT OPTION: a
Upthrust = weight fluid displacement 0.040 - 0.024 = PVg
0.016 = 800 x V x 10
V = 2.0 x 106
8
Which of the following will reduce the frequency of oscillation of a simple pendulum?
A
Increasing the mass of the bob
B
Decreasing the mass of the bob
C
Increasing the length of the string
D
Decreasing the length of the string
CORRECT OPTION: c
9
A force of 20 N applied parallel to the surface of a horizontal table, is just sufficient to make a block of mass 4kg move on the table. Calculate the coefficient of friction between the block and the table. (g = 10ms2)
A
0.05
B
0.20
C
0.50
D
0.80
CORRECT OPTION: c
μ= F/mg = 20/40 = 0.5
10
A barometer can be used in determining the I. height of a mountain II. depth of a mine III. dew point. Which of the following is/are correct?
A
I, II and III
B
II and III only
C
I and III only
D
I and II only
CORRECT OPTION: d
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