# 2006 - WAEC Physics Past Questions and Answers - page 1

1
Which of the following phenomena causes capillary of liquids in tubes of narrow bore?
A
viscosity
B
surface tension
C
osmosis
D
brownian motion
correct option: b
2
Which of the following physical quantities are derived? i. Area ii. Thrust iii. Pressure iv. Mass
A
i, ii, iii and iv
B
i, ii and iii only
C
i, ii and iv only
D
i and iii only
correct option: b
3
A block of volume 3 x 105m3 and density 2.5 x 103 kg m-3 is suspended from a spring balance with $$\frac{2}{3}$$ of its volume immersed in a liquid of density 900 kg m-3. Determine the reading of the spring balance [g = 10ms-2]
A
0.18N
B
0.57N
C
0.75n
D
0.93N
correct option: b
Volume immersed solid = 3 x 105 x $$\frac{2}{3}$$

= 2 x 105m3

Mass of liquid displaced = ev

= 2 x 105 x 900 = 18 x 107 kg

Upthrust = 18 x 107 x 10

= 7.8 x 109N

Mass of solid = ev

= 2.5 x 103 x 105

= 7.5 x 108

Weight of solid = 7.5 x 108 x10 = 7.8 x 109

Reading = 0.75 - 0.18 = 0.57N
4
A solid body will float in a liquid if its
A
density is less than that of a liquid
B
mass is equal to that of the liquid
C
density is greater than that of the liquid
D
mass is less than that of the liquid
correct option: a
5
An object is said to undergo oscillatory motion when it moves
A
in an erratic manner
B
to and fro about a fixed point
C
in a circular path
D
along a continuous path from the starting point
correct option: b
6
A body is rotating in a horizontal circle of radius 2.5m with an angular speed of 5 rad s-1. Calculate the magnitude of the radial acceleration of the body
A
62.50ms-2
B
31.25ms-2
C
12.50ms-2
D
10.00ms-2
correct option: c
$$\alpha = \frac{W_2 - W_1}{t} = \frac{5}{1} = 5 rad$$/s2

9 = $$\alpha$$r

= 5 x 2.5 = 12.50m\s2
7
A moving car of mass 800 kg experiences a frictional force of 200N. If it accelerates 2 ms-2, calculate the magnitude of the force applied to the car
A
600N
B
1000N
C
1600N
D
1800N
correct option: d
F = M + FF 800 x 2 = 200

= 1800N
8
Uniform speed occurs when there is equal change of
A
distance in equal times
B
displacement in equal times
C
velocity in equal times
D
acceleration in equal times
correct option: a
9
A car accelerates uniformly from rest at 5 ms-2. Determine its speed after 10s
A
50.0ms-1
B
25.0ms-1
C
2.0ms-1
D
0.5ms-1
correct option: a
V = u + at = 0 + 5 x 10 = 50m/s2