a) \displaystyle 36 km/h = 10 m/s och \displaystyle 72 km/h = 20 m/s
\displaystyle \Rightarrow I = (20 m/s)(1500kg)-(10 m/s)(1500kg) = 15kNs
b) \displaystyle I = Fs \Rightarrow F = \frac{15nKs}{10s} = 15kN
