Question

When two blocks connected by a spring move towards each other under mutual interaction,
A. (a) Their velocities are equal and opposite
B. (b) Their accelerations are equal and opposite
C. (c) The forces acting on them are equal and opposite
D. (d) Their momenta are equal and opposite

Answer 1

Correct Answer - C::D
When two blocks connected by a spring move towards each other, the law of conservation of momentum leads to the following results:
I `vecp_2=-vecp_1` i.e., at any instant two blocks will have equal and opposite momenta.
ii. `vecv_2=-(m_1/m_2)vecv_1`, i.e., two blocks move in opposite directions with lighter block moving faster.
iii. It is quite clear that forces acting on them will be equal and opposite. Acceleration may be different if masses are different. So options (c) and (d) are correct.