Question

An object moving with constant acceleration changes its speed from 20 m/s to 60 m/s in 2.0 s. What is the acceleration? (b) How far did it move in this time?

Answer 1

Answer:

a)$20\ \rm m/s^2$

b) 80 m

Explanation:

Given:

• Initial velocity of the object, u=20 m/s
• Final velocity of the object, v=60 m/s
• Time taken, t=2 s

Using Equation of motion we have

a)Let a be the acceleration of the object

$v=u+at\\60=20+2a\\a=20\ \rm m/s^2$

b) Let d be the distance covered by the object given by

Using equation of motion we have

$2ad=v^2-u^2\\2\times20\times d=60^2-20^2\\d=80\ \rm m$