Figure 2.1 shows how the velocity $v$ of cars P and Q varies with time $t$. The two cars move in the same direction along a straight road, and car P passes car Q at time $t = 0$.
(a)[1]
The speed limit for cars on this road is $100\,\text{km h}^{-1}$. State and explain whether car Q is above the speed limit.
(b)[2]
Calculate the acceleration of car P.
(c)[3]
Determine the distance between the two cars at time $t = 12\,\text{s}$.
(d)[2]
From $t = 12\,\text{s}$, each car keeps the velocity it has at $t = 12\,\text{s}$. Determine the time $t$ when car Q passes car P.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Since $30\,\mathrm{m\, s^{-1}} = 108\,\mathrm{km\, h^{-1}}$ or $100\,\mathrm{km\, h^{-1}} = 28\,\mathrm{m\, s^{-1}}$, the speed limit is exceeded” …