A body of mass `5 xx 10^(3) g` kg moving with speed 2 m/s collides with a body of mass `15 xx 10^(3) kg` inelastically & sticks to it. Then loss in K.E. of the system will be :

Options

A. `7.5 kJ`
B. `15 kJ`
C. `10 kJ`
D. `5 kJ`

Answer

A

Explanation

Loss in K.E. `= 1/2 (M_(1)M_(2))/(M_(1)+M_(2)) V^(2) (1-e^(2))`
`= 1/2 xx (5xx10^(3)xx15 xx 10^(3))/(20xx 10^(3)) xx (2)^(2) (1-(0)^(2))`
`= 1/2 xx (75 xx 10^(3))/(20) xx 4`
`= 7.5 kJ`