Question

A car of mass 2500 kg moving with a velocity 10 m / sec brought to rest in 5 sec by applying brakes.Find the retarding force produced by the brakes.

Answer 1

Answer:-

Given:-

• Initial velocity (u) = 10 m/s
• Final velocity (v) = 0 m/s [Since it will come on rest]
• Mass (m) = 2500 kg
• Time taken (t) = 5 s

To Find:-

Regarding force (F) produced by the brakes.

_____________...

Finding acceleration:-

We know,

a = (v-u)/t

or, a = -u/t

where,

• a = Acceleration,
• v = Final velocity,
• u = Initial velocity &
• t = Time.

So,

a = - (10 m/s)/5s

➵ a = (-10 m/s)/5s

➵ a = -2 m/s² ...(Acceleration)

Finding retardation force:-

We know,

F = ma

where,

• F = Force,
• m = Mass &
• a = Acceleration.

∴ F = (2500 kg) (-2 m/s²)

➵ F = - 5000 kg m s^-2

➵ F = - 5000 N ...(Force against motion)

Therefore, the retarding force was (-5000 N) against the path of motion.