Consider a drop of rain water having mass 1 g falling from a height of 1 km . It hits the ground with a speed of 50 m/s . Take g constant with a value - Physics MCQ NEET 2017 2026 | ExamTest.live

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Consider a drop of rain water having mass 1 g falling from a height of 1 km . It hits the ground with a speed of 50 m/s . Take g constant with a value 10 m/s^{2} . The work done by the (i) gravitational force and the (ii) resistive force of air is:

Solution & Step-by-step Explanation

1. Work by gravity W_{g} = m g h = (1 0^{- 3} kg) \times (10) \times (1000) = 10 J .2. Work-Energy Theorem: W_{g} + W_{ai r} = Δ K E = \frac{1}{2} m v^{2} - 0 . 10 + W_{ai r} = \frac{1}{2} (1 0^{- 3}) (50)^{2} = \frac{1}{2} \times 1 0^{- 3} \times 2500 = 1.25 J . W_{ai r} = 1.25 - 10 = - 8.75 J .

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Consider a drop of rain water having mass 1 g falling from a height of 1 km . It hits the ground with a speed of 50 m/s . Take g constant with a value 10 m/s^{2} . The work done by the (i) gravitational force and the (ii) resistive force of air is:

(i) - 10 J (ii) - 8.25 J

(i) 1.25 J (ii) - 8.25 J

(i) 100 J (ii) 8.75 J

(i) 10 J (ii) - 8.75 J

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