Question

the speed time graph of a car is shown below the car weighs 1000 kg find how much force is applied by the brakes in 5 sec so that the car comes to halt by the sixth second​

Answer 1

Answer:

Force (F) = mass (m) × acceleration (a)

Time taken by force to stop car = 6 - 5 = 1

second

Initial velocity (i.e. velocity at B) = 15 m/s

Final velocity (at point C) = 0 m/s

using equation v = u + at

a = (v-u) / t = (0 -20) / 0.02 = -15 m/s2

(-ve sign indicates that it is retardation )

Force applied by brakes = 1000 × -15 = -15000 N

= - 15 KN