Physics Past Questions and Answers

A uniform cylindrical hydrometer of mass 20g and cross sectional area 0.54cm² floats upright in a liquid. If 25cm of its length is submerged, calculate the relative density of the liquid. (Density of water = 1 gcm^-3)

A 1.54
B 1.48
C 1.25
D 0.80

Question 717:

The apparent weight of a body wholly immersed in water is 32N and its weight in air is 96N. Calculate the volume of the body. (Density of water = 1000kgm^-3, g = 10ms^-3)

A 8.9 x 10m^-3m³
B 6.4 x 10m^-3m³
C 3.2 x 10m^-3m³
D 3.0 x 10m^-3m³

Question 718:

A wooden block of mass 1.6kg rest on a rough horizontal surface, if the limiting friction force between the block and the surface is 8N. Calculate the coefficient of friction. (g = 10ms^-2)

A 0.6
B 0.5
C 0.3
D 0.2

Question 719:

A ball bearing is gently released from rest and allowed to fall through a viscous fluid. Which of the following statements about the motion is correct?

A Its acceleration decreases before terminal velocity is attained
B When terminal velocity is attained the acceleration of the fluid becomes zero
C Its velocity increases before terminal velocity is attained
D There is no resultant force on the ball before it attains terminal velocity

Question 720:

The driver of a car moving with uniform speed of 40ms^-1 observes a truck approaching from the opposite direction with a speed of 20ms^-1. Calculate the speed of the car relative to that of the truck

A .5ms^-1
B 2.0ms^-1
C 20.0ms^-1
D 60.0ms^-1