2016 - WAEC Physics Past Questions & Answers - page 1

1
The dimensions of momentum are
A
MLT
B
ML-1T-1
C
MLT-1
D
ML-1T
CORRECT OPTION: c
Momentum = kgms-1 = MLT-1
2
A student measures the volume of a liquid using a measuring cylinder. What else needs to be measured by the student in order to determine the density of the liquid?
A
depth of the liquid in the cylinder
B
mass of the cylinder
C
mass of the liquid
D
tempersture of the liquid
CORRECT OPTION: c
3
The diagram given, represents the graph of stress against strain for an elastic wire. The point Q on the graph is the
A
elastic linit
B
breaking point
C
yield point
D
proportional limit
CORRECT OPTION: b
4
A ball is dropped from the top of a tower. Due to air resistance,it reaches terminal velocity. Which of the following statement(s) about its motion is/are correct? i. The acceleration of the ball is zero. ii. The net force on the ball is zero. iii. The velocity of the ball increases.
A
i only
B
i and ii only
C
ii and iii only
D
i, ii and iii
CORRECT OPTION: a
5
Which of the following substances lowers the surface tension of water?
A
metal
B
sand
C
detergent
D
paper
CORRECT OPTION: c
6
An object of volume 400cm3 and 2.5gcm-3 is suspended from a spring balance with half its volume immersed in water. Determine the reading on the spring balance. (Density of water = 1gcm-3)
A
1200g
B
1000g
C
800g
D
400g
CORRECT OPTION: c
Mass = density x volume

400 x 2.5 = 1000g

Loss in mass = volume x density

= \(\frac{400}{2}\) x 1 = 200g

Reading on spring balance = 1000 - 200g = 800g
7
The diagram given illustrates a force-distance graph for the motion of a wooden block. Determine the work done on the block when moved through a distance of 5m.
A
4J
B
15J
C
5J
D
100J
CORRECT OPTION: d
W = FS = 20 X 5

= 100J
8
The two person of a body undergoing a uniformly accelerated motion are (10s, 10ms-1) and (30s, 50ms-1). On the velocity-time graph pf the body.
A
0.5ms-2
B
2.0ms-2
C
10.0ms-2
D
40.0ms-2
CORRECT OPTION: b
Slope = a = \(\frac{\deltav}{\deltat}\)

= \(\frac{50 - 10}{30 - 10}\)

= 2.0ms-2
9
At a birthday party, the celebrant pops a corked fruit wine. If the cork shoots out of the bottle at an angle of 40o to the horizontal and travels a horizontal distance of 4.50m in 1.25s. Calculate the initial speed of the cork.
A
4.2ms-1
B
4.7ms-1
C
5.6ms-1
D
7.1ms-1
CORRECT OPTION: b
R = Ucos\(\theta\) x t

U = \(\frac{R}{Cos \theta \times t}\)

= \(\frac{4.50}{Cos40N.25}\)

= 4.699m/s
10
A uniform metre rule is balanced on a fulcrum placed at the 35cm mark by suspending a mass of 120g at the 10cm mark. Calculate the mass of the metre rule.
A
60g
B
80g
C
120g
D
200g
CORRECT OPTION: d
Clock-wise moment = Anti-clock wise

15 x m = 5 x 10

m = 200g
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