Q
A ball thrown vertically upward returns to its starting level after 13.5 s. What was its launch speed? Take g = 10 m/s².
RRB Group-D
31/10/2018 / Shift I
2018
✓ Answer:
A
67.5 m/s
Total flight time T = 2u/g, so u = gT/2 = 67.5 m/s.