A tap is 45 m above the floor. Drops are released at equal time intervals. When the first drop hits the floor, the fourth drop is just released. Taking g = 10 m s⁻², enter the release interval in seconds multiplied by 10.
Physics · Kinematics Part-1 (one dimension) · Motion under gravity
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Question

A tap is 45 m above the floor. Drops are released at equal time intervals. When the first drop hits the floor, the fourth drop is just released. Taking g = 10 m s⁻², enter the release interval in seconds multiplied by 10.

Physics · Kinematics Part-1 (one dimension) · Motion under gravity

G1 Physics · Accepted Answer

Time for the first drop to fall: 45 = 5T², so T = 3 s. From first to fourth release there are 3 equal intervals, hence interval = 1 s. Multiplied by 10 gives 10.