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Question
A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done against the gravitational force will be (g = 10 m s–2)
Options
6 ×103 J
6 J
0.6 J
zero
Solution
zero
Explanation:
The gravitational force on the bag, i.e. the weight of the bag is in a vertically downward direction whereas the distance moved by her is in the horizontal direction. It means that the force and displacement are perpendicular to each other, therefore no work is done.
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