A body of mass `0.5 kg` is projected under the gravity with a speed of `98 m//s` at an angle of `30^(@)` with the horizontal. The change in momentum (in magnitude) of the body when it strikes the ground is

Options

A. 24.5 N-s
B. 49.0 N-s
C. 98.0 N-s
D. 50.0 N-s

Answer

B

Explanation

Initially body is at rest.
`therefore`Initial momentum `p_(1)=mxx0`
`p_(1)=0`
final momentum `p_(2)=mv`
`=0.5xx98=49N`
change in momentum `=p_(2)-p_(1)`
`=49-0=409N-s`