A hiker is walking along a straight road that runs exactly east–west
PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A hiker is walking along a straight road that runs exactly east–west. The centre of a village V is first taken as the origin x=0. All positions east of V are positive.
Stage 1: The hiker starts from a point P that is 5km west of V.
Stage 2: The hiker walks until she reaches a point Q that is 3km east of V.
At point Q, the hiker decides to describe all subsequent positions with respect to Q itself, treating Q as the new origin.
Answer the following:
(a) Calculate the displacement of the hiker from P to Q using the original origin V.
(b) Express the position of the starting point P with respect to the new origin Q.
(c) Recalculate the displacement of the hiker from P to Q using Q as the origin and show that it matches the value obtained in part (a), stating clearly the sign convention used.