15. •• A pole vaulter at the Relativistic Olympics sprints past you to do a vault at a speed of 0.65c. When he is at rest, his pole is 7.0 m long.

(a) What length do you perceive the pole to be as he passes you, assuming his relative velocity is parallel to the length of the pole?

(b) How long does it take the pole to pass a given location on the track according to a track-based observer?

(c) Repeat part

(b) from the vaulter’s reference frame and explain why the two answers are different.