9702/Oct Nov/11/2015/Q14

Two blocks X and Y are falling through a vacuum in a uniform gravitational field, as shown.

Block X has weight 2w.
Block Y has weight w.
The blocks do not move apart.
Which value best represents the force exerted by block X on block Y?

A 0
B w
C 1.5w
D 2w

Solution:
Answer: A

The figure below explain the free fall object (without air resistance) is not affected by mass or shape. Both blocks are fall at the same rate in vacuum. Thus, no force exerted by block X on block Y.

Reference: PYQ - Oct/Nov 2015 Paper 11 Q14