Question

If a bus travelling at 20m/s is subjected to a steady deceleration of 5m/s (second square) , how long will it take to come to rest?

Answer 1

, $$\begin{gathered} given: \\ acceleration,a=-5\left(\frac{m}{s^2}\right) \\ initialvelocity,u=20m/s \\ timet,v=finalvelocity \\ nowu\sin gmotionequationinonedimension \\ v=u+at; \\ 0=20-5t(puttingallvaluesinequation) \\ 5t=20 \\ t=\frac{20}{5} \\ t=4second. \end{gathered}$$