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प्रश्न
A man of mass 50 kg climbs up a ladder of height 15 m. Calculate:
- the work done by the man,
- the increase in his potential energy. (g = 9.8 m s-2)
उत्तर
Mass of man = 50 kg
Height of ladder, h2 = 15 m
(i) Work done by man = mgh2
= 50 × 9.8 × 15 = 7350 J
(ii) increase in his potential energy:
Height, h2 = 15 m
Reference point is ground, h1 = 0m
Gravitational potential energy = Mg (h2 - h1)
= 50 × 9.8 × (15 - 0)
= 50 × 9.8 × 15
= 7350 J
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