2026 · Q19
An object is launched horizontally from a height of 45 m above the ground with a speed of 10 m/s. The time at which the object will hit the ground is: (Take g = 10 m/s2)
General KnowledgePhysics
- A6 s
- B4 s
- C2 s
- D3 s
Explanation
The horizontal launch speed affects only the range, not the time of flight, which is governed purely by vertical fall. Time to fall height h is t = sqrt(2h/g) = sqrt(2x45/10) = sqrt(9) = 3 s. Options of 6 s, 4 s, or 2 s do not satisfy the free-fall kinematics. Note: UPSC's published key marks option C (2 s), but the calculation unambiguously gives 3 s.