A ball of mass 1 kg moving with a speed of `10 ms^(-1)` rebounds after a pefect elastic collision with the floor. Calculate the change in linear momentum of the ball.

Explanation

u=-20 cm
f=10 cm
`1/(f)=1/v-1/u`
`1/v=1/(f)+1/u`
`1/v=1/10+1/(-20)`
`1/v=1/10-1/20`
`v=1/20 rArr` v=20 cm
Nature of the image real enlarged and inverted image.
(ii)Given : mass =1 kg , speed = `10 ms^(-1)`
`therefore` Initial momentum = mu = 1 x 10 =10 kg `ms^(-1)`
Final momentum = mv =- 10 `ms^(-1)`
Change in momentum =final momentum - Initial momentum
=mv-mu
=-10-10
Change in momentum =-20 kg `ms^(-1)`