Question

Two bodies of masses 5 kg and 3 kg are moving towards each other with 2 and 4 metre per second respectively then velocity of centre of mass is

Answer 1

Hope you got it right

Answer 2

Vcm= M1V1+M2V2/M1+M2

but the particles are moving in opp direction

then angle becomes 180

so the formula is

Vcm=M1V1-M2V2/M1+M2

substitute the values given in the question

the answer is 0.25