Answer to Question #319917 in Mechanics | Relativity for Jake

Question

To avoid a potential collision with wildlife cross the road, the driver of a car traveling 105 km/h fully applies the brakes to stop as quickly as possible. If the car stops 3.8 s after the brakes are applied, what is the braking distance ?

Answer 1

Explanations & Calculations

• Since the deceleration is constant/ assumed constant / normally constant, one can apply $\small s = \large \frac{(u+v)t}{2}$ to calculate the distance travelled in time t.

$\qquad\qquad \begin{aligned} \small 105\,kmh^{-1}&=\small \frac{105\times1000}{3600}=29.17\,ms^{-1}\\ \small s&=\small \frac{(0+29.17)\times3.8\,s}{2}\\ &=\small 55.4\,m \end{aligned}$