Question

Two bodies of 2 Kg & 4 Kg are moving with velocities 20 m/s and 10 m/s respectively

towards each other under mutual gravitational attraction. Find the velocity of their centre of

mass in m/s.


(A) 5 (B) 6 (C) 8 (D) Zero

Answer 1

We know if two bodies are moving opposite to each other then.
m1u1 - m1u1 =(m1+m2)v. {v1=v1=v bcz they start moving with a common velocity v}

Let's substitute. m1=2kg,m2=4kg,u1=20m/s,u2=10m/s v=?m/s

2(20)-4(10)=(2+4)v
40-40=6v
0=6v
v=0/6
v=0m/s...
Thanks for the question