Four cyclists and start from the same point at the same instant and ride for exactly
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
Four cyclists P,Q,R and S start from the same point O at the same instant and ride for exactly 4min, each choosing a different route as described below:
• P: straight 800m due north.
• Q: straight 600m due east.
• R: 300m north, then 300m east, then 300m south.
• S: rides once around a square track of side 200m, starting and ending at O.
(a) Arrange the four cyclists in descending order of the magnitudes of the distances they have travelled.
(b) Arrange the four cyclists in descending order of the magnitudes of their displacements from point O at the end of 4min.
(c) Without performing detailed numerical calculations, give a clear reasoning for each of the two orderings obtained in parts (a) and (b).