K.C.S.E Physics Q & A - MODEL 2019PP1QN17

K.C.S.E Physics Q & A - MODEL 2019PP1QN17

​(a) State what ¡s meant by  Brownian Motion. 
(b) Figure 8 shows the graph of velocity against time For a small steel ball Falling in a viscous liquid.

​(i) Describe the motion of the steel ball as represented by part OA
(ii) Explain why the velocity of A and B is constant
(c)A student throws a tennis ball vertically upwards from the ground and it lands back after 8 seconds.( acceleration due to gravity g =10m/s2)
Determine the:
(i) maximum height reached by the ball
iii) velocity with which the ball hits the ground.

answers

​(a) Continuous random motion of particles. 
(b) (i) It accelerates, velocity increases. 
(ii) As the ball falls through the fluid, the Viscous drag increases  until the sum of the Viscous drag and the upthrust becomes equal  the weight of the steel ball, hence the resultant force becomes zero.