An object slides without friction down a slope from rest through a vertical height of 45 m (g = 10 m/s squared). What is its speed at the bottom?
Answer and explanation
Correct answer: D. 30 m/s
- Step 1: Energy is conserved: mgh = 1/2 m v squared.
- Step 2: v = sqrt(2 x 10 x 45) = 30 m/s.
Answer
30 m/s.
Why not the others: 900 m/s, 60 m/s and 45 m/s do not fit.
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