Question

A 200kg vehicle moving with a speed of 20 m/s is brought to rest in distance of 100 meter. Find the

force acting on the cars by brakes.​

Answer 1

Given:-

• Mass of Vehicle = 200kg

• Initial velocity of vehicle = 20m/s

• Final velocity = 0m/s

• Distance travelled = 100m

To Find:-

• Force acting the cars by brakes

Formulae used:-

• v² - u² = 2as

• F = ma

Where,

• v = Final Velocity
• u = Initial Velocity
• a = Acceleration
• s = Distance
• F = Force
• m = Mass

Now,

→ v² - u² = 2as

→ (0)² - (20)² = 2 × a × 100

→ 0 - 400 = 2 × a × 100

→ -400 = 200a

→ a = -400/200

→ a = -2m/s²

The Retardation of vehicle is -2m/s²

Therefore,

→ F = ma

→ F = 200 × -2

→ F = -400N

Hence, The Force exerted on the car by brakes is -400N.