Question

A body of mass m is projected with initial speed u at an angle with the horizontal. The change in momentum of
body after time t is
(1) mu sine
(2) 2musino
(3) mgt
(4) Zero​

Answer 1

Answer:

mgt

Explanation:

assume the angle to be θ

at initial point that is at lowest point 'u' will have two components one is

usinθ(vertical) and other one is ucosθ (horizontal)

at any instant i.e 't' vertical component will be= usinθ-gt and horizontal componenet will remain unchanged =ucosθ (as there is no acceleration in that direction)

initial linear P = musinθj+mucosθi

final P(at any instant)=mucosθ+mu(sinθ-gt)j

ΔP=final P - initial P

hence we'll get -mgtj

IΔPI=mgt