Question

body of mass m is projected with initial speed u at and angle theta with horizontal the change in momentum of the body after t time​

Answer 1

s we know that a projectile action is a combination to

horizontal and vertical movement. The vertical part of initial velocity ‘ u ’

always remains steady ,i.e. in this case , u x= u cos o , throughout the

motion. So alter in momentum in horizontal direction is zero

Now analyzing the vertical movement we know initial velocity

in vertical course u y = u sin o.

After time t , v y = u sin o – g t , ( equation of motion

i.e v = u + a t )

Thus, Change in momentum in vertical track = m . v y – m . u

y 

= m . ( u sin o – g t ) - ( m . u sin o )

= - m g t