At exactly 2:00, the hour and minute hands are separated by 60°. If they first coincide after N/11 minutes, find N.

Question

G1 Physics · Accepted Answer

Minute hand speed = 6°/min and hour hand speed = 0.5°/min. Their relative angular speed is 5.5°/min = 11/2°/min. At 2:00 the minute hand is 60° behind the hour hand. Time to gain 60° is t = 60 ÷ (11/2) = 120/11 min. Hence N = 120.