Question

A body of mass m is projected with initial speed u at an angle

Answer 1

Explanation:

As we know that a projectile motion is a combination to horizontal and verticle motion.

The vetical component of intial velocity ‘u’ always remains constant ,i.e. in this case ,ux=ucoso, throughout the motion.

So change in momentum in horizonal direction is 0(zero).

Now analysing the vertical direction motion we know intial velocity in vertical direction

uy=usino.

After time t,vy=usino-gt,(using eq. of motion ,

v=u+at)

Thus, Change in momentum in vertical direction

=m.vy-m.uy

=m.(usino-gt)-(m.usino)

=-mgt

=-mgtNOTE: Take the vector consideration.