Question

A 1 kg ball his the wall with a speed of 5 m per second and renounce off the wall in opposite direction with the same speed. what is the change in the magnitude of the ball?​

Answer 1

Answer:

Impulse = Change in momentum

ΔP=P

f

−P

i

=m(v

f

−v

i

)=0.1(30−(−20))=0.1×50=5Ns

Answer 2

Answer:

We know that area under force-time graph gives change in linear momentum

area=

2

1

F

o

T=change in linear momentum

v

1

=−u, negative sign represents initial velocity is in negative x- direction according to our sign convention

v

2

=u,final velocity is in positive x- direction

initial momentum=m(−u)=−mu

final momentum=mu

change in linear momentum=2mu

2

1

F

o

T=2mu

⟹F

o

=

T

4mu