Consider elastic collision of a particle of mass m moving with a velocity u with another particle of the same mass at rest. After the collision the projectile and the struck particle move in directions making angles \[{{\theta }_{1}}\]and \[{{\theta }_{2}}\]respectively with the initial direction of motion. The sum of the angles. \[{{\theta }_{1}}+{{\theta }_{2}},\]is [UPSEAT 2004]

Consider elastic collision of a particle of mass m moving with a veloc

1.	Consider elastic collision of a particle of mass m moving with a velocity u with another particle of the same mass at rest. After the collision the projectile and the struck particle move in directions making angles \[{{\theta }_{1}}\]and \[{{\theta }_{2}}\]respectively with the initial direction of motion. The sum of the angles. \[{{\theta }_{1}}+{{\theta }_{2}},\]is [UPSEAT 2004]
A.	\[45{}^\circ \]
B.	\[90{}^\circ \]
C.	\[135{}^\circ \]
D.	\[180{}^\circ \]
Answer» C. \[135{}^\circ \]