A body of mass falls freely from rest through a height of . What is its speed on reaching the ground? (take , answer in m/s)
Answer and explanation
Correct answer: C. 10
- Step 1: For a body dropped from rest in a uniform gravitational field, mechanical energy conservation gives impact velocity (independent of mass).
- Step 2: Substitute gravitational acceleration and vertical descent : .
- Step 3: Evaluating the radical gives impact speed .
Answer
10.
Why not the others: 20 doubles the impact speed; 5 is the fall height; 250 multiplies by mass .
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