2011 - WAEC Physics Past Questions and Answers - page 2
11
Two simple pendulum A and B of equal lengths and of masses 5g and 20g respectively are located in the same environment. The periods TA and TB of their respective oscillations are related by the equations
A
TA = 4TB
B
TA = \(\frac{1}{4} T_B\)
C
TA = TB
D
TA = 5TB
correct option: c
The period of a simple pendulum is dependent on the frequency. It is also dependent on the length of the pendulum but not the mass. Since the two pendulums have equal length, then their periods are equal as well.
12
An object of mass 5.0 kg moves with a velocity of 10ms-1. Calculate its momentum.
A
50.0 kgms-1
B
15.0 kgms-1
C
2.0 kgms-1
D
0.5 kgms-1
13
A coin is pushed from the edge of a laboratory bench with a horizontal velocity of 15.0 ms-1. If the height of the bench from the floor is 1.5m, calculate the distance from the foot of the bench to the point of impact with the floor [g = 10ms-2]
A
0.75m
B
2.25m
C
8.22m
D
15.00m
correct option: c
S = U\(\sqrt{\frac{2h}{g}}\)
= 15\(\sqrt{\frac{2 \times 1.5}{10}}\)
= 8.22m
Users' Answers & Comments= 15\(\sqrt{\frac{2 \times 1.5}{10}}\)
= 8.22m
14
Which of the following statements correctly defines a simple machine? A device
A
that can produce electric current
B
which can only carry people from one place to another
C
with which work can be done easily
D
which changes the state of rest or of uniform motion of an object
correct option: c
Users' Answers & Comments15
The radius of a wheel is 30.0 cm and that of its axle is 6.0cm. Calculate the effort required to lift a load of 120.0N using this machine. Assuming 100% efficiency
A
600.0N
B
40.0N
C
24.0N
D
20.0N
correct option: c
V.R = \(\frac{R}{r} = \frac{30}{6} = 5\)
\(\gamma = \frac{M.A}{V.R} \times \frac{100}{1} \)
M.A = \(\frac{100 \times 5}{100} = 5\)
Effort = \(\frac{L}{M.A} = \frac{120}{5}\)
= 24N
Users' Answers & Comments\(\gamma = \frac{M.A}{V.R} \times \frac{100}{1} \)
M.A = \(\frac{100 \times 5}{100} = 5\)
Effort = \(\frac{L}{M.A} = \frac{120}{5}\)
= 24N
16
A hypsometer is used for determining
A
steam point
B
relative humidity
C
ice point
D
relative density
correct option: a
Users' Answers & Comments17
Which of the following equations shows how how the linear expansivity (\(\alpha\)) and the cubic expansivity (\(\gamma\)) of a material are related?
A
\(\gamma = \alpha\)
B
\(\gamma = 1 - \alpha\)
C
\(\gamma = 2 \alpha\)
D
\(\gamma = 3 \alpha\)
correct option: d
Users' Answers & Comments18
Which of the following statements about anomalous expansion of water are correct? i. There is contraction between 0oC and 4oC. ii. There is expansion between 0oC and 100oC. iii. The volume is minimum at 4oC. iv. The volume is maximum at 4oC
A
i and ii only
B
ii and iii only
C
i and iii only
D
ii and iv only
correct option: c
Users' Answers & Comments19
Which of the following assumptions is not valid for an ideal gas ?
A
molecules of a particular gas are identical
B
molecules moves freely throughout the volume of the container
C
force of attraction between molecules is negligible
D
molecules move at constant speed between collisions
correct option: c
Users' Answers & Comments20
A body is pulled over a distance of 500m by a force of 20N. If the power developed is o.4 kW, calculate the time interval during which the force is applied
A
0.2s
B
2.5s
C
25.0s
D
250.0s
correct option: c
t = \(\frac{fs}{p} = \frac{20 \times 500}{0.4 \times 1000} = 25s\)
Users' Answers & Comments