PHYSICS · Multi-part · CBSE · Physics · Motion in a Straight Line · Motion in a Straight Line
Problem
Two cyclists, Alice and Ben, start at the same instant from villages that are 20km apart on a straight east–west road. Alice departs from the western village riding east at a constant speed of 6.0ms−1. Ben departs from the eastern village riding west at a constant speed of 4.0ms−1. Treat the motion as one–dimensional along the road and neglect any effects of terrain or wind.
(a) Calculate the time after departure at which the two cyclists pass each other.
(b) Determine the distance each cyclist has traveled from his or her respective starting point by the moment they pass.
(c) At the instant they meet, a third cyclist, Cara, starting from rest at the western village, begins riding east at 5.0ms−1. Determine the time required for Cara to reach Ben's original starting point, assuming Ben continues westward at his original speed for the entire interval.
(d) Explain how the choice of reference frame could simplify or complicate the analysis performed in parts (a)–(c).