## Task 2 - 020922

A car is traveling at a speed of $100 \frac{\mathrm{km}}{\mathrm{h}}$. It is being braked.

a) In what time will it come to a stop if, due to braking, its speed decreases by $5 \frac{\mathrm{m}}{\mathrm{s}}$ every second?

b) What braking distance does it cover in this time?
a) From the formula $v=a t$ we obtain

$$
t=\frac{v}{a}=\frac{\frac{100}{3.5} \frac{\mathrm{m}}{\mathrm{s}}}{5 \frac{\mathrm{m}}{\mathrm{s}^{2}}} \approx 5.56 \mathrm{~s}
$$

b) In this time, the car covers a distance of $s=\frac{a}{2} t^{2} \approx 77.3 \mathrm{~m}$.