0
$\begingroup$

Is newton's third law valid for rigid bodies? Say, if we have a bullet hit on a rod which is vertically placed on a rough floor. Friction is just sufficient sp that the rod rotates and does not slide. Just before collision the bullet makes an angle of 45 deg with the horizontal.

We have to find $\omega$ after collision.

Will the bullet exert an impulse on the rod which is equal to the impulse exerted by the rod on the bullet?

$\endgroup$
  • $\begingroup$ Yes - Newton's 3rd Law is valid for one particle, or many particles stuck together in the shape of a rod or a bullet. $\endgroup$ – Brionius Apr 26 '15 at 15:53
0
$\begingroup$

Yes. Some of the impulse force is used in work which rotates the rod, and some of the impulse force is used in work which changes the bullet's trajectory. The distribution of impulse force between the rod and the bullet is equal.

$\endgroup$
  • $\begingroup$ maybe I made a calc error, but using this, I wasnt able to get the right answer. $\endgroup$ – Saurabh Raje Apr 26 '15 at 16:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.