JAMB Physics Past Questions & Answers - Page 277

1,381.

An inclined plane which makes an angle of 30^o with the horizontal has a velocity ratio of

0.866

0.50

Correct answer is A

V.R = \(\frac{1}{sin\theta}\)

= \(\frac{1}{sin30}\)

= 2

1,382.

A body of mass 10kg rests on a rough inclined plane whose angle of tilt \(\theta\) is variable. \(\theta\) is gradually increased until the body starts to slide down the plane at 30^o. The coefficient of limiting friction between the body and the plane

0.30

0.50

0.58

0.87

View answer & explanation

Correct answer is C

n = tan 30 = 0.58

1,383.

A stone of mass m kg is held h meters above the floor for 50s. The work done in joules over this period is

mgh

\(\frac{mgh}{50}\)

View answer & explanation

Correct answer is D

work = mgh(no motion)

1,384.

To keep a vehicle moving at a constant speed v, requires power P, from the engine. The force provided by the engine is

\(\frac{p}{v}\)

\(\frac{1}{2}\) v

\(\frac{p}{v^2}\) v

View answer & explanation

Correct answer is A

power = speed x force

force = \(\frac{power}{speed}\)

1,385.

Which of the following statements are correct about an object in equilibrium under parallel forces?

i. the total clockwise moments of the forces about any point equals the total anti-clockwise moments about the same point.
ii. the total forces in one direction equals the total forces in the opposite direction.
iii. the resolved components along the x-axis equals the resolved components along the y-axis.

i and ii only

i and iii only

ii and iii

i, ii, and iii only

View answer & explanation

Correct answer is A

No explanation has been provided for this answer.