Two particles A and B having masses m and $$3m$$ are initially at rest at a separation $$4m$$. They start moving towards each other under the influence of mutual gravitational force of attraction. After some time, if displacement of A is $$0.1$$ m, then magnitude of displacement of B at that instant is

Question

Two particles A and B having masses m and $$3m$$ are initially at rest at a separation $$4m$$. They start moving towards each other under the influence of mutual gravitational force of attraction.  After some time, if displacement of A is $$0.1$$ m, then magnitude of displacement of B at that instant is

Infinity Learn · Accepted Answer

$$(2)As$$ external force acting on the system is zero, position of its centre of mass remains unchanged.∴   $$mA+mB$$ × rcm  $$=$$  mA.$$rA+$$  mB.rB⇒  $$mA+mB$$ ×  Δrcm  $$=$$  mA.Δ$$rA+$$  mB.ΔrB⇒  $$m+3m$$ ×$$0$$  $$=$$  m  ×  $$1+3m$$  ×  ΔrB⇒   ΔrB $$=$$−$$13$$  metre.Therefore B moves by $$1/3$$ metre in opposite direction.

Two particles A and B having masses m and 3m are initially at rest at a separation 4m. They start moving towards each other under the influence of mutual gravitational force of attraction. After some time, if displacement of A is 0.1 m, then magnitude of displacement of B at that instant is

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material