Two stones, P and Q, produce readings of 49 N and 98 N respectively on the same spring balance when weighed one after the other at the same place on Earth.
(a) Determine the mass of each stone.
(b) Which stone possesses greater inertia? State the reason for your choice.
(c) If both stones are dropped from the same height in vacuum, will one reach the ground earlier than the other? Give a brief justification for your answer.