2006 - WAEC Physics Past Questions and Answers - page 2
11
which of the following statements about simple harmonic motion is correct? The
A
total mechanical energy is always conserved
B
linear acceleration is directed to any variable point
C
linear acceleration varies inversely with displacement
D
period of oscillation varies linearly as acceleration due to gravity
correct option: a
Users' Answers & Comments12
A force acting on a body causes a change in the momentum of a body from 12 kg ms-1 to 16kg ms-1 in 0.25. Calculate the magnitude of the impulse
A
28.0Ns
B
20.0Ns
C
4.0Ns
D
0.8Ns
13
Which of the following source of energy is renewable?
A
petroleum
B
charcoal
C
hydro
D
nuclear
correct option: c
Users' Answers & Comments14
A stone of mass 2.0kg is thrown vertically upward with a velocity of 20.0 ms-1, calculate the initial kinetic energy of the stone
A
200J
B
400J
C
800J
D
1600J
correct option: b
K.E = \(\frac{1}{2}Mv^2 = \frac{1}{2} \times 2 \times 20^2 = 400J\)
Users' Answers & Comments15
Which of the following statements about the mouth piece of a telephone is correct? It converts sound energy into
A
acoustic energy
B
mechanival energy
C
electrical energy
D
heat energy
correct option: c
Users' Answers & Comments16
The potential energy in an elastic string of force constant K which has been extended by X metres is expresses as
A
\(\frac{1}{2}k \Box ^2\)
B
\(k \Box ^2\)
C
\(\frac{1}{2}k \Box \)
D
\(k \Box \)
correct option: a
Users' Answers & Comments17
The engine of a train produces a force of 3000N when moving at 30.ms-1. calculate the power of the engine
A
1.00 x 102W
B
3.00 x 104W
C
9.00 x 104W
D
3.00 x 105W
18
The velocity ratio of an inclined plane, inclines at an angle \(\theta\) to the horizontal can be expressed as
A
(sin \(\theta)^{-1}\)
B
\(\sin \theta\)
C
(cos \(\theta)^{-1}\)
D
\(\cos \theta\)
correct option: a
Users' Answers & Comments19
A block and tackle system has six pulleys. a force of 50N applied to it lifts a load of weight W. If the efficiency of the system is 40%, calculate W
A
300N
B
200N
C
140N
D
120N
correct option: d
M.A = \(\frac{E \times V.R}{100} = \frac{40 \times 6}{100} = \frac{12}{5}\)
W = M.A x effort
= \(\frac{12}{5} \times 50 = 120N\)
Users' Answers & CommentsW = M.A x effort
= \(\frac{12}{5} \times 50 = 120N\)
20
The sagging of overhead electrical cables is the consequence of
A
linear expansivity
B
superficial expansivity
C
cubic expansivity
D
conductivity
correct option: a
Users' Answers & Comments