JAMB Physics Past Questions & Answers - Page 255

1,271.

The mechanical advantage(MA) of an inclined plane depends on

A.

its length

B.

its height

C.

the product of its length and height

D.

the ratio of its length to its height

Correct answer is D

No explanation has been provided for this answer.

1,272.

If a beaker is filled with water it is observed that the surface of the water is not horizontal at the glass-water interface. This behavior is due to

A.

friction

B.

viscosity

C.

surface tension

D.

evaporation

Correct answer is C

No explanation has been provided for this answer.

1,273.
1,274.

A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]

A.

40%

B.

35%

C.

20%

D.

15%

Correct answer is C

P.E = mgh = 1000m joules

K.E = \(\frac{1}{2}\)mv2 = 200m joules

%converted = \(\frac{200m}{1000m}\) x 100

= 20%

1,275.

A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2 for 4s. Calculate the work done by the force

A.

8JQ

B.

10J

C.

32J

D.

160J

Correct answer is C

X = ut + \(\frac{1}{2}\)at2

= (0 x 4) + (\(\frac{1}{2}\) x 0.1 x 4 x 4)

= 0.8m

workdone = force x distance

= 40 x 0.8

= 32J