Question

A car traveling at 45 km/h starts to brake, and comes to a stop over a distance of 18 m. Calculate the acceleration

Answer 1

Answer:

Acceleration, $a=8.68\ m/s^2$

Explanation:

Given that,

Initial speed of a car, u = 45 km/h = 12.5 m/s

Final speed, v = 0 (as they comes to rest)

Distance, d = 18 m

We need to find the acceleration of the breaking car. Using third equation of motion as follows :

$v^2-u^2=2ad\\\\\text{Where a is acceleration of the car}\\\\a=\dfrac{v^2-u^2}{d}\\\\a=\dfrac{(12.5)^2}{18}\\\\a=8.68\ m/s^2$

So, the acceleration of the braking car is $8.68\ m/s^2$.