Question

A motorcycle is moving with a velocity of 90 km/h and it takes 5 seconds to stop after the breaks are applied.calculate the force exerted by the brakes on the motorcycle if its mass along with the rider is 200 kg.

Answer 1

Convert 90 km/h to m/s

=> (90 x 5/18) m/s

=> 25 m/s


Now,

=> V = u+at

=> 0 = 25 + a x 5

=> -25 = a x 5

=> -25/5 = a

=> a = -5 m/s^2


Now,

Force = mass x Acceleration

=> F = ma

=> F = {200 x (-5)} Kg m/s^2

=> F = -1000 Kg m/s^2

=> F = -1000 N.




Be Brainly

Answer 2

mass of motorcycle along with the rider , M = 200g
initial velocity of motorcycle, u = 90km/h = 90 × 5/18 = 25 m/s

a/c to question,

motorcycle takes 5 sec to stop after the breaks are applied.

so, final velocity of motorcycle, v = 0

use formula, v = u + at

0 = 25 + a × 5 => a = -5 m/s²

hence, retardation applied on motorcycle is 5m/s² .

now, use Newton's 2nd law,

e.g., F = Ma

M = 200kg, and a = 5m/s²

hence, F = 200 × 5 = 1000N

hence, 1000N force exerted by the brakes on the motorcycle