Question

A ball of mass 2kg strikes against the wall with the velocity of 10 metre per second and rebound with 2 metre per second its change in momentum is​

Answer 1

Dear friend,

● Answer -

∆p = 24 kgm/s

◆ Explaination -

Direction of velocity changes when ball rebounds back from the wall.

u = 10 m/s

v = -2 m/s

Initial momentum of the ball is -

pi = mu

pi = 2 × 10

pi = 20 kgm/s

Final momentum of the ball is -

pf = mv

pf = 2 × -2

pf = -4 kgm/s

Change in momentum is calculated by -

∆p = pi - pf

∆p = 20 - (-4)

∆p = 24 kgm/s

Therefore, change in momentum of ball is 24 kgm/s.

Thanks for asking..

Answer 2

A ball of mass 2Kg strikes against the wall with velocity of 10m/s. and rebound with 2m/s.

from above data,

initial velocity , u = 10m/s

final velocity , v = -2 m/s [ after striking, velocity of ball is just opposite in direction of its initial velocity ]

mass of ball, m = 2kg

so, initial momentum, Pi = mu = 2 × 10 = 20kgm/s

final momentum , Pf = mv = 2 × (-2) = -4kgm/s

so, change in momentum = final momentum - initial momentum

= Pf - Pi

= -4 Kgm/s - 20 Kgm/s

= -24 Kgm/s

hence, change in momentum of ball is -24 Kgm/s .

and hence, magnitude of charge in momentum = 24 Kgm/s