(a)[2]
Describe the motion of the car shown in Fig. 1.1.
(b(i))[1]
At time $t = 10\,\text{s}$ the car's engine is switched off. The brakes are not used. Name two forces acting on the car that bring about the change in motion after $t = 10\,\text{s}$.
(b(ii))[1]
Suggest why Fig. 1.1 becomes a curve after $t = 10\,\text{s}$.
(c(i))[2]
From $t = 10\,\text{s}$ to $t = 20\,\text{s}$ the car's speed changes from $18\,\text{m s}^{-1}$ to $11\,\text{m s}^{-1}$. The mass of the car is $1200\,\text{kg}$. Calculate the change in momentum of the car in this interval. State the unit of your answer.
(c(ii))[2]
Calculate the average resultant force on the car over this interval.