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A raindrop of mass `1g` falling from a height of `1km` hits is the ground with a speed of `50 ms^(-1)`. Which of the following statements is correct? `("Taking" g= 10ms^(-2))`.A. The loss of potential energy of the drop is 10 JB. The gain in kinetic energy of the drop is 1.25 JC. The gain in kinetic energy of the drop is not equal to the loss of potential energy of the drop.D. All of these |
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Answer» Correct Answer - D Here, m=1 `g= 10^(-3)` kg, h = 1 km = 1000 m `g = 10 m s^(-2), v = 50 m s^(-1)` Loss of potential energy of the drop `=mgh=(10^(-3) kg)(10 m s^(-2)) (1000 m) = 10 J`...(i). Hence, option (a) is correct. Gain in kinetic energy of the drop `=1/2mv^2=1/2xx(10^(-3) kg)(50 m s^(-1))^2=1.25 J` Hence, option (b) is correct. From (i) and (ii), we get Loss of potential energy of the drop `ne` Gain in kinetic energy of the drop. Hence, option (c) is also correct. |
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