Physics (AS & A Level) · May / June 2023 · Paper 11 · Question 9

A small ball is held at the surface of liquid oil in a container. The ball is released from rest and falls through the oil. The ball has velocity v. A viscous (drag) force F acts on the ball. Which graph could show the variation with v of F?

1. AGraph A: F increases with v, starting from origin, curving upwards
2. BGraph B: F increases with v, starting from origin, curving to a plateau
3. CGraph C: F starts at zero, rises to a peak then decreases to zero
4. DGraph D: F starts high and decreases with v towards zero

As printed in the paper