What is the kinetic energy of a 5 kg body moving at 7 m/s?
Answer and explanation
Correct answer: B. 122.5 J
- Step 1: KE = ½mv². Step 2. KE = ½ × 5 × 7² = 122.5 J. Answer: 122.5 J. Why not the others: 245 J is what you get if you forget the factor ½. 17.5 J is what you get if you forget to square the speed. 61.25 J is what you get if you halve twice.
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