2004 - WAEC Physics Past Questions and Answers - page 2
11
A machine of velocity ratio 5 is used in lifting a load with an effort of 500N. If the machine is 80% efficient. Determine the magnitude of load
A
2500N
B
2000N
C
900N
D
625N
correct option: b
M.A = \(\frac{Eff \times V.r}{100} = \frac{80 \times 5}{100} = 4\)
Load = effort x M.A
= 4 x 500 = 2000N
Users' Answers & CommentsLoad = effort x M.A
= 4 x 500 = 2000N
12
The speed of an object in rectilinear motion can be determine from the
A
area under a velocity-time graph
B
area under a distance-time graph
C
slope of a distance-time graph
D
slope of a velocity-time graph
correct option: c
Users' Answers & Comments13
A body is said to be moving with uniform acceleration if it experiences equal
A
increase in velocity at equal time intervals
B
decreases in velocity at equal time intervals
C
increases in speed at equal time intervals
D
decreases in speed at equal time intervals
correct option: a
Users' Answers & Comments14
A body is dropped from a certain height above the ground level, falls with uniform
A
speed
B
velocity
C
acceleration
D
retardation
correct option: d
Users' Answers & Comments15
A body of mass 8kg moving with a speed of 30ms-1 is brought to rest in 2.5s by a constant retarding force. Calculate the magnitude of the force
A
240N
B
96N
C
20N
D
9N
16
A force acting on a body causes a change in the momentum of the body from 12kg ms-1 to 16kg ms-1 in 0.2s. calculate the magnitude of the force
A
140.0N
B
20.0N
C
4.0N
D
0.8N
17
The bob of a single pendulum has a mass of 0.02kg. Determine the weight of the bob [g = 10ms-2]
A
0.02N
B
0.20N
C
20.00N
D
200.00N
18
A ball bearing is projected vertically upwards from the ground with a velocity of 15ms-1. Calculate the time taken by the ball to return to the ground [g = 10ms-1]
A
1.5s
B
3.0s
C
5.0s
D
7.5s
correct option: b
t = 2\(\frac{(v - u)}{g} = 2\frac{(0 - 15)}{-10}\)
\(\frac{2 \times 15}{10}\) = 3.0s
Users' Answers & Comments\(\frac{2 \times 15}{10}\) = 3.0s
19
A loaded spring performs simple harmonic motion with an amplitude of 5cm. If the maximum acceleration of the load is 20cm s-1, calculate the angular frequency of the motion
A
2 rad s-1
B
4 rad s-1
C
5 rad s-1
D
10 rad s-1
20
When compared with water, mercury is preferred as a thermometric liquid because
A
has a higher density
B
has lower specific heat capacity
C
exhibits anomalous thermal expansion
D
contains molecules which have very strong adhensive forces
correct option: d
Users' Answers & Comments