An athlete on a straight training track begins at the origin and runs eastward with…
PHYSICS · Multi-part · CBSE · Physics · Motion in a Straight Line · Motion in a Straight Line
Problem
An athlete on a straight training track begins at the origin and runs eastward with an initial velocity of +12ms−1. She experiences a constant westward (negative) acceleration of 3.0ms−2 for the next 10s, after which she continues at the velocity she then has.
Respond to all parts, showing detailed reasoning, algebraic steps, and correctly signed answers.
(a) Determine the athlete’s velocity at t=10s.
(b) At what time after the start, if ever, does the athlete momentarily come to rest? Show how you arrive at your answer.
(c) Calculate the total distance the athlete covers during the first 10s.
(d) For the first 10s, compute (i) the average velocity and (ii) the average speed of the athlete. Explain clearly why these two quantities differ in sign and/or magnitude.