Question

A car moves 500 m in 20 seconds. What is its final velocity if it was moving 5 m/s to begin with?

Answer 1

distance(s) = 500m

time = 20 seconds

initial velocity(u) = 5 m/s

final velocity(v) = ?

Therefore, using the equation of motion

`\begin{gathered} s=ut+(1)/(2)at^2 \\ \end{gathered}`
`\begin{gathered} 500=5(20)+(1)/(2)a(20)^2 \\ 500=100+(400a)/(2) \\ 400=200a \\ a=(400)/(200) \\ a=2m/s^2 \end{gathered}`

let's find the final velocity

`\begin{gathered} v=u+at \\ v=5+2*20 \\ v=5+40 \\ v=45\text{ m/s} \end{gathered}`