NEET2015PhysicsCenter of Mass, Momentum and CollisionActual
On a frictionless surfaces, a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle θ to its initial direction and has a speed v 3 . The second block's speed after the collision is:
Options
- A3 4 v
- B3 2 v
- C3 2 v
- D2 2 3 v
Correct answer
D. 2 2 3 v
Step-by-step solution
In elastic collision energy of system remains same. so, (( KE )_ before collision =( KE )_ after collision ) Let speed of second body after collision is ( v ^ ). ( aligned & 1 2 Mv ^2+0= 1 2 M ( v 3 )^2+ 1 2 M ( v ^ )^2 & v ^ = 2 2 3 v aligned )