Question

cars moving along a staright line at a speed of 54km/h stops in 5s after the brakes are applied (a) find the acceleration ,assuming it to be constant

Answer 1

$$\begin{gathered} Initialvelocity=54km/h=15m/s \\ finalvelocity=0 \\ timet=5s \\ V=u+at \\ 0=15+5a \\ a=-3m/s^2 \end{gathered}$$