Physics · May / June 2019 · Paper 12 · Question 23

In low-pressure hydrogen, there are no forces between the molecules except during collisions with each other. Which statement describes the motion of a molecule between one collision and the next?

1. AIt moves with changing speed and continuously changes direction.
2. BIt moves with changing speed in a straight line.
3. CIt moves with constant speed and continuously changes direction.
4. DIt moves with constant speed in a straight line.

As printed in the paper