(a)[1]
Define the quantity momentum.
(b)[1]
Calculate the change in momentum of the object from $t = 0$ to $t = 12\ \text{s}$.
(c)[2]
Calculate the magnitude of the resultant force acting on the object.
(d)[1]
Describe how the speed of the object changes from $t = 0$ to $t = 8.0\,\text{s}$.
(e)[2]
Using Fig. 2.1, explain why the resultant force acting on the object during the first $8.0\,\text{s}$ of its motion cannot be air resistance.
(f)[3]
At $t = 0$, the displacement $d$ of the object is zero. On Fig. 2.2, sketch how $d$ varies with time $t$ from $t = 0$ to $t = 12\,\text{s}$. Numerical values of $d$ are not needed.