Question

A car travels for 5 seconds with a soeed of 72km h -1 and then applies beakes and retards uniformlyfor the next 5 seconds till it comes to rest. The total distance travelled by the car is

Answer 1

Answer:

72 km/h = 20 m/s

If retardation means retardation acceleration (deceleration) AND it is constant, then:

Vavg = V/2 = 10 m/s

Vavg = d/t = 50/t

t = 50/Vavg = 50/10 = 5 s

deceleration = V/t = 20/5 = 4 m/s² ANS