A rock and a rock are released from rest at the same height above the ground and fall…
PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A 2kg rock and a 1kg rock are released from rest at the same height h above the ground and fall freely. Which statement best compares their mechanical energies just before impact?
(a) Both rocks have the same kinetic energy because they reach the same speed.
(b) The 2kg rock has four times the kinetic energy of the 1kg rock.
(c) The 2kg rock has twice the kinetic energy of the 1kg rock.
(d) Their kinetic energies cannot be compared without knowing the release height h.