A sphere of mass 50 g moving with velocity of 10m/s collide with the rest block at mass 950 g and embeded . The kinetic energy lost by sphere will be `…….`

Options

A. 1
B. 0.95
C. 0.5
D. 0.05

Answer

B

Explanation

Initial Kinetic energy = `1/2 mv^(2)`
` = 1/2 xx 0.05 xx100`
K = 2.5 J
According the conservation of momentum
`MV +mv = (M+m)v`
` 0.05 xx10 + 0 = 1v`
` :. `Final kinetic enegy =`1/2 (M+m) v^(2)`
` = 1/2 xx 1xx 0.25`
`:. K = 0.125 J `
` :. K/K =(0.125)/(2.5)`
` :. (K-K)/K = 100 = (2.5-0.125)/(2.5) xx100`
` = 23.75 xx4`
` = 95.00 ` %