Q.
Statement-1 : Two particles moving in the same direction do not lose all their energy in a completely inelastic collision.
Statement-2 : Principle of conservation of momentum holds true for all kinds of collisions.
AIEEEAIEEE 2010Work, Energy and Power
Solution:
If it is a completely inelastic collision then
$m_{1}v_{1} +m_{2}v_{2} = m_{1}v +m_{2}v$
$v = \frac{m_{1}v_{1}+m_{2}v_{2}}{m_{1}+m_{2}}$
$K.E = \frac{p^{2}_{1}}{2m_{1}} +\frac{p^{2}_{2}}{2m_{2}} $
as $\vec{p_{1}}$ and $\overrightarrow{p_{2}}$ both simultaneously cannot be zero
therefore total KE cannot be lost.
