Table 1.1 shows a selection of physical quantities. Use ticks (✓) to show which quantities are vectors and which are scalars.
A constant resultant force $F$ is applied to a car of mass $m$. It starts from rest and travels along horizontal ground with constant acceleration $a$. When the car has moved a distance $s$, its speed is $v$.
Using the idea of work done on the car, show that the car’s kinetic energy $E_{K}$ is given by $E_{K} = \frac{1}{2}mv^{2}$.
The mass of the car is $920\,\text{kg}$. At time $t = 0$, the car is at rest. At time $t = 5.8\,\text{s}$, its velocity is $17\,\text{m s}^{-1}$. Calculate the kinetic energy of the car at time $t = 5.8\,\text{s}$.
From $t = 0$ to $t = 5.8\,\text{s}$, the work done against resistive forces is $4.7 \times 10^4\,\text{J}$. Find the car’s average output power over this interval.
At $t = 5.8\,\text{s}$, the car’s speed becomes constant. State and explain whether the car’s output power is greater than, less than, or the same as the output power just before $t = 5.8\,\text{s}$.