Question

A car travels at a speed of 18 m/s. It accelerates at a rate of 3.00 m/s/s. Find the distance it travels in 4.0 s of accelerated motion. What is the car's speed at that moment?

Answer 1

Step-by-step explanation:

The distance it travels during 4 seconds:

`x \: =( vi * t )\: + 0.5a {t}^(2) \\ \\ x \: = (18 * 4) + 0.5(3)( {4}^(2) ) \\ x \: = 96 \: m`

The final speed is:

`{u}^(2) = {v}^(2) + 2ax \\ u = \sqrt{ {18}^(2) + 2(3)(96)} = 30 \: (m)/(s)`