Question

A 1000kg vehicle moving with a speed of 20ms-1 is brought to rest in a distance of 50 metre by applying beakes (1) find the acceleration (2) calculate the unalanced force acting on the vehicle. (3) the actual force applied by the brakes will be slightly less than that calculated in, why? give reasons​

Answer 1

Answer:

Vehical Mass = 1000 kg

Initial Velocity (that is speed) let it be u = 20 ms-1

Final Velocity let it be v= 0ms-1

Distance travelled = 50 m

let the acceleration be "a"

From equation => v2 = u2 + 2as

putting all value

(0m/s)2 = (20m/s)2 + 2*a*50 m

0m2/s2 = 400m2/s2 + 100a m

0m2/s2 - 400m2/s2 = 100a m    

(Side changing)

-400m2/s2 = 100a meter

-400m2/s2 / 100 m = a          

(side changing and cancelling m with m2)

-4m/s2 = a

a = -4 m/s2

This shows that the acceleration is in opposite direction that means it is retardation.

retardation = 4m/s2

Explanation: