Question

A truck of mass 50kg has its speed reduced from 4m/s to 1.5m/s in 30s. Find the braking force (assumed constant )

Answer 1

$F=ma$

$v=v_0-at\to a=\frac{v_0-v}{t}=\frac{4-1.5}{30}=0.083(m/s^2)$

$F=50\cdot0.083=4.17(N)$