Question

A car moving with the speed of 90km/hr. It's driver is his a child in the middle of the road at 200m. Whether he will hit the child or not. If he immediately applies brake and the time is 5 second

Answer 1

Answer:

u = 90km/h = 90 x 5/18 = 25 m/s

v = 0 m/s

t = 5s

Using the First Equation of Motion

v = u + at

0 = 25 + 5a

5a = -25

a = -25/5

a = -5 m/s^2

Using the Third Equation of Motion

v^2 - u^2 = 2as

- 25^2 = 2 x (-5) x s

625 = 10s

s = 625/10

s = 62.5m

No, the car will not hit the child as the distance travelled during deceleration is less than the distance of the child from the car.