Get premium membership and access revision papers with marking schemes, video lessons and live classes.

Processing. Please wait.

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 between A and B is constant.

Answer Text:
(i)- The steel ball accelerates towards the bottom because its weight is greater than the sum of upward forces.
(ii)- The sum of upward forces (viscosity+upward) becomes equal to weight and the resultant force is zero. The ball therefore attains a constant
velocity.