Question

A car accelerates uniformly in a straight line

from rest at the rate of 2.8 m/s^2.

What is the speed of the car after it has
traveled 69 m?
Answer in units of m/s.

Answer 1

Recall that

`{v_f}^2={v_i}^2=2a\Delta x`

The car starts from rest, so
`v_i=0`, and we get

`{v_f}^2=2\left(2.8(\rm m)/(\mathrm s^2)\right)(69\,\mathrm m)\implies v_f\approx19.66(\rm m)/(\rm s)`