Question

Two particles moving towards each other with speeds of 4m/s have masses of 4kg and 6kg .They collide and stick to each other. What will be the speed of combined mass after collision?​

Answer 1

Answer:

Say the velocity one way (left to right) is positive hence the other way (right to left) be negative

Then by law of conservation of momentum,

m1v1 + m2v2 + (m1+m2)v where v is the required speed.

=> 4x4 + 6x(-4) = (4+6)v

=> v = -8/10 = -0.8 m/s

Negative sign indicates the resultant motion is towards the side the body of 6kg was originally moving i.e. right to left.