1997 - WAEC Physics Past Questions and Answers - page 1

An object of mass 0.40 kg attached to the end of a string is whirled around in a horizontal circle of radius 2.0m with a constant speed of 8(ms^{-1}). Calculate the angular velocity of the object

An object falls freely from a height of 25m onto the roof a building 5m high. Calculate the velocity with which the object strikes the roof (g=10(ms^{-2})

A ball of mass 0.1kg approaching a tennis player with a velocity of 10(ms^{-1}),is hit back in the opposite direction with a velocity of 15(ms^{-1}). If the time of impact between the racket and the ball is 0.01s, calculate the magnitude of the force with which the ball is hit

Two blocks of the same dimension, one steel and the other wooden are dropped simultaneously from the same height. If they fall freely neglecting air resistance the

Two forces 3N and 4N act on a body in directions due north and due east respectively. Calculate their equilibrant

A missile weighing 400N on the earth surface is shot into the atmosphere to an altitude of 6.4 x (10^{-6})m. Taking the earth as a sphere of radius 6.4 x (10^{-6})m and assuming the inverse-square law of universal gravitation, what would be the weight of the missile at that altitude?

A solid plastic cube of side 0.2m is submerged in a liquid density of 0.8kg(m^{-3}). Calculate the upthrust of the liquid on the cube (g=10(ms^{-2})

A piece of copper of mass 30g loses 60J of heat energy. If the specific heat capacity of copper is 400J(kg^{-1}K^{-1}), Calculate the change in the temperature of the copper

Steel bars each of length 3m at 28°C are to be used for constructing a rail line. If the linear expansitivity of the steel is 1 x (10^{-5}K^{-1}),what is the safety gap that must be left between the successive bars if the highest temperature expected is 40°C?

Which of the following explains why a thick glass cup cracks when boiling water is poured into it?