Exam-style question
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A student calculates the gravitational potential energy of a 10 kg object raised to a height of 5 m as 500 J. Use approximate values to check whether this calculated answer is realistic.
Model answer
What a good answer should say
- Using the approximate value of g as 10 N/kg, the estimated gravitational potential energy is 500 J, which is realistic.
Explanation
Why this works
This question assesses the ability to use approximate values to verify calculations. The formula for gravitational potential energy is Ep = m x g x h.
Substituting m = 10 kg, g ≈ 10 N/kg, and h = 5 m gives Ep = 10 kg x 10 N/kg x 5 m = 500 J, confirming the student's calculation is realistic.
Common mistake
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