WAEC Physics Past Questions & Answers - Page 162

806.

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 answer is A

No explanation has been provided for this answer.

808.

Which of the following type of motion does a body undergo when acted upon by a couple?

A.

vibrational

B.

translational

C.

rotational

D.

random

Correct answer is C

No explanation has been provided for this answer.

810.

A wheel and axle of radii 800mm and 200mm respectively is used to raise a body of weight 800N by the application of 250N. Calculate the efficiency of the machine

A.

85%

B.

80%

C.

60%

D.

20%

Correct answer is B

V.R = \(\frac{R}{r} = \frac{800}{200} = 4\)

M.A = \(\frac{L}{E} = \frac{800}{250} = 3.2\)

y = \(\frac{M.A}{v.R} \times \frac{100}{1} = 80\)%