Question

A motorcycle is moving with a velocity of `90 km//h` and it takes `5 second` to stop after the brakers are applied. Calculate the force exerted by the brakers on the motorcycle if its mass alongwith the rider is `200 kg`

Answer 1

Here, initial velocity, `u= 90km//h=(90xx1000m)/(60xx60s)=25 m//s`
time taken, `t=5` s, final velocity , `u=0`, force, `F=?` total mass, `m =200kg`
As `F= ma=(m(v-u))/t= (200(0-25))/5= -1000N`.
Negative sign is for opposing force.