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InterviewSolution
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A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 ms^(-2),with what velocity will it strike the ground ? After what time will it strike the ground? |
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Answer» Solution :Here, `u =0,a = 10 ms ^(-2), s =20 m.` `2as = v ^(2) - u^(2)` `therefore 2 xx 10 ms ^(-2) xx 20 m = v ^(2) -0` `therefore v ^(2) = 400 m ^(2) s ^(-2) therefroe v = 20 ms ^(-1)` `v = u + at` `therefore 20 ms ^(-1) = 0 + 1 0 ms ^(-2) xx t` `therefore 20 ms ^(-1) = 10 ms ^(-2) xx t` `therefore t = (20 ms ^(-1))/(10 ms ^(-2)) =2s ` The ball will strike the GROUND with a velocity of `20 ms ^(-1).` It will strike the ground after 2s. |
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