If an object with uniform acceleration (or deceleration) has a speed of 2ms at t=0 and moves a total of 20 m by t=4, what was the object's rate of acceleration?

1 Answer
Jul 2, 2016

a=1.5ms2

Explanation:

This is interesting. The question gives us an ambiguity as to whether the acceleration is positive or negative. We can solve this using the first kinematic equation.

We'll establish the variables first. u=2ms, t=4, x=20m

We'll use the first kinematic equation now.
x=ut+12at2
So, that ends us with 20=24+12a16
Rearranging, 208=8a12=8a1.5ms2=a