Assertion :An object of mass $m_{1}$ and another of mass $m_{2} (m_{2} > m_{1})$ are released from certain distance. The objects move towards each other under the gravitational force between them. In this motion, centre of mass of their system will continuously move towards the heavier mass $m_{2}$ . Reason: In a system of a heavier and a lighter mass, centre of mass lies closer to the heavier mass.

Question

Q. Assertion: In the equation,

y = A sin (k x - ω t)

, particle starts from its mean position

x = 0

and moves towards negative

y -

axis.
Reason: The wave corresponding to given equation is travelling towards positive

x -

direction.

Answer 1

Centre of mass remains stationary as only internal forces acts on system. hence assertion is incorrect. In a system of a heavier and a lighter mass,Center of mass lies closer to the heavier mass. hence reason is correct.

Answer 2

Option D is correct.