A student carries the same metal block first to the surface of the Moon and then back to Earth. The block is weighed at both places using (A) a beam balance and (B) a spring balance.
(i) Explain why instrument (A) gives the same reading on the Moon as on Earth.
(ii) Explain why instrument (B) gives different readings at the two places.
(iii) Define inertial mass and gravitational mass.
(iv) State which of the two instruments measures inertial mass and which measures gravitational mass, giving reasons.