Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when the velocity of A is v and that of B is 2v. The velocity of centre of mass of the system is

Question

Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when the velocity of A is v and that of B is 2v. The velocity of centre of mass of the system is (A) zero (B) v (C) 2v (D) 3v

Tardigrade Admin · Accepted Answer

Initially both particles were at rest so vcm=0. As external force on the system is zero. Therefore velocity of centre of mass remain unaffected.

Q. Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when the velocity of A is v and that of B is 2v. The velocity of centre of mass of the system is

zero

v

2v

3v

Initially both particles were at rest so $v_{c m} = 0.$ As external force on the system is zero. Therefore velocity of centre of mass remain unaffected.

Q. Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when the velocity of A is v and that of B is 2v. The velocity of centre of mass of the system is

zero

v

2v

3v

Initially both particles were at rest so vcm​=0. As external force on the system is zero. Therefore velocity of centre of mass remain unaffected.

Initially both particles were at rest so $v_{c m} = 0.$ As external force on the system is zero. Therefore velocity of centre of mass remain unaffected.