A box slides down a smooth slope of height 5 m starting from rest. Taking the acceleration due to gravity as 10 m per second squared, what is its speed at the bottom?
Answer and explanation
Correct answer: C. 10 m/s
- Step 1: Energy conservation: mgh = 1/2 m v^2, so v = root(2gh). Step 2. v = root(2 x 10 x 5) = root 100 = 10 m/s. Answer: 10 m/s. Why not the others: 5 m/s: That is the height, not the speed. 50 m/s: That is not the square root of 2gh. 100 m/s: That is v^2, not v.
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