A 5 kg block is lifted 2 m at constant speed. How much work is done against gravity? (g = 10 m/s2)
Answer and explanation
Correct answer: B. 100 J
- Step 1: Work = mgh. Step 2. = 5 x 10 x 2 = 100 J. Answer: 100 J. Why not the others: 10 J: That is only mass times height. 50 J: That is mass times g, the weight. 25 J: That divides the work by 4 without cause.
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