Question

A bullet of mass 0.06kg moving with a speed of 500m/s is brought to rest in 0.01s .Find the impulse and the average force of the blow.

Answer 1

Given :
u=500m/s. v= 0 m/ s. m= 0.06kg
t=0.01s
impulse= mass x change in velocity
= 0.06x (0-500)
= 30 kg m/s
Force = mX( v-u)/ t
=30 / 0.01
= 3000N

Answer 2

Answer:Given that,

              m= 50gram

                  =0.05kg

              u=500m/s

              v=0m/s

              t=0.1sec.

We know that,

              Impulse=m(v-u)

                            =0.05(0-500)

                            =0.05×(-500)

                            =-25 N.

Again,

      Average force=m(v-u)/t

                               =-25/0.1

                               =-250 N.

Therefore,

     The impulse is -25N

    And the average force is -250N.

   

Explanation:

You are thinking that force's answer is always come in positive.

Yess you are right but this is a Retarding or resistive force. Retarding force's answers are always come in negative.

For this reason this answer has  come in minus sign.

Thanks guys ...... Good luck for your great and bright future