Question

The car traveling 56.0 km/h is 25.0 m towards a haystack when the driver brakes. The car hits the haystack 2.11 s later. How fast is the car traveling at impact? Answer in m/s

Answer 1

36.13 m/s

Step-by-step explanation:

initial speed, u = 56 km/h = 15.56 m/s

distance, s = 25 m

t = 2.11 s

Let the speed of the car at the impact is v and the acceleration is a.

Use second equation of motion

`s=ut+(1)/(2)at^(2)`

`25=1.56 * 2.11+(1)/(2)* a * 2.11^(2)`

a = 9.75 m/s^2

Use first equation of motion

v = u + at

v = 15.56 + 9.75 x 2.11

v = 36.13 m/s