2005 - WAEC Physics Past Questions and Answers - page 2
11
The frequency of a swinging pendulum is the
A
number of complete oscillations the pendulum makes in a second
B
number of amplitudes the bob makes in a second
C
angle the bob swings through in a second
D
distance the bob covers in a second
correct option: a
Users' Answers & Comments12
Which of the following about an object performing simple harmonic motion is correct? Its acceleration
A
is maximum at the extreme ends
B
is constant and directed towards a fixed point
C
is zero when it is displayed from the equilibrum position
D
varies linearly with the displacement from a fixed point and is directed towards the fixed point
correct option: b
Users' Answers & Comments13
A body of mass 5kg moving with a velocity of 10ms-1 collides with a stationary body of mass 6kg. If the two bodies stick together and move in the same direction after their collision, calculate their common velocity
A
4.55ms-1
B
12.00ms-1
C
30.00ms-1
D
50.00ms-1
correct option: a
\(M_1V_1 + M_2U_2 = V(M_1 + M_2)\)
5 x 10 + 6 x 0 = V(5 + 6)
V = \(\frac{50}{11} = 4.55\)m/s
Users' Answers & Comments5 x 10 + 6 x 0 = V(5 + 6)
V = \(\frac{50}{11} = 4.55\)m/s
14
Fuel was consumed at a steady rate of 5.0 x 10-2kg per second in a rocket engine and ejected as a gas with a speed of 4 x 103ms-1. Determine the thrust on the rocket
A
20N
B
80N
C
200N
D
800N
correct option: c
F = ma = \(\frac{mv}{t} = \frac{5 \times 10^{-2} \times 4 \times 10^{3}}{1}\)
= 200N
Users' Answers & Comments= 200N
15
Which of the following quantities has the same unit as energy?
A
power
B
work
C
force
D
momentum
correct option: b
Users' Answers & Comments16
Which of the following source of energy is renewable?
A
sun
B
petroleum
C
coal
D
uranium
correct option: a
Users' Answers & Comments17
The lower and upper fixed point of a thermometer are 30mm and 180mm respectively. Calculate the temperature in degrees Celsius when the thermometer reads 45mm
A
10.0oC
B
15.0oC
C
20.0oC
D
30.0oC
correct option: a
100....180
A......45
0......30
\(\frac{45 - 30}{180 - 30} = \frac{A - 0}{100 - 0}\)
A = \(\frac{15 \times 100}{150} = 10^oC\)
Users' Answers & CommentsA......45
0......30
\(\frac{45 - 30}{180 - 30} = \frac{A - 0}{100 - 0}\)
A = \(\frac{15 \times 100}{150} = 10^oC\)
18
A body of mass m, has a specific heat capacity s, and a heat capacity c. If the temperature of the body changes by \(\theta^oC\), Which of the following equation is correct?
A
ms\(\theta\) = mv-1
B
ms = C
C
ms = s\(\theta\)
D
ms = c\(\theta\)
19
An immersion heater rated 400W, 220V is used to heat a liquid of mass 0.5kg. If the temperature of the liquid increases uniformly at the rate of 2.5oC per second, calculate the specific heat capacity of the liquid. [Assume no heat is lost]
A
1100Jkg-1K-1
B
320Jkg-1K-1
C
200Jkg-1K-1
D
176Jkg-1K-1
correct option: b
pt = mc\(\theta\)
C = \(\frac{pt}{m \theta}\)
= \(\frac{400 \times 1}{0.5 \times 2.5}\)
= 320Jkg-1K-1
Users' Answers & CommentsC = \(\frac{pt}{m \theta}\)
= \(\frac{400 \times 1}{0.5 \times 2.5}\)
= 320Jkg-1K-1
20
Water falls through a height of 50m. Determine the temperature rise at the bottom of the fall. [Neglect energy losses. Specific heat capacity of water = 4200Jkg-1 K-1, g = 10ms2]
A
0.119oC
B
0.840oC
C
1.190oC
D
8.400oC
correct option: a
mgh = mc\(\theta\)
\(\theta = \frac{gh}{c} = \frac{10 \times 50}{4200}\)
= 0.119oC
Users' Answers & Comments\(\theta = \frac{gh}{c} = \frac{10 \times 50}{4200}\)
= 0.119oC