What is the kinetic energy of a 5 kg object moving at 4 m/s?
Answer and explanation
Correct answer: D. 40 J
- Step 1: Kinetic energy = 1/2 x mass x speed squared.
- Step 2: 1/2 x 5 x 4 squared = 40 J.
Answer
40 J.
Why not the others: 80 J: the factor one half was left out. 10 J: the speed was not squared. 20 J: an extra factor of one half was applied.
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