A lift accelerates upward at 2 m/s². A man throws a ball vertically upward relative to the lift at 12 m/s. Take g = 10 m/s². Find the return time to the man (s).
Physics · Mixed Chapter
JEE Main Practice

Question

A lift accelerates upward at 2 m/s². A man throws a ball vertically upward relative to the lift at 12 m/s. Take g = 10 m/s². Find the return time to the man (s).

G1 Physics · Accepted Answer

Step 1: In the lift frame, effective gravitational acceleration is gₑff = g + a = 10 + 2 = 12 m/s² downward. Step 2: Relative displacement of the ball is y = 12t − ½(12)t². Step 3: On returning to the man's hand, y = 0; the nonzero root is t = 2×12/12 = 2 s.