Question

can anyone solve this question

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Answer 1

when ball is drop from a height then it's initial velocity(u) is zero and H is 20m , a= +g ,use 2nd equation of motion , H=ut+1/2at^2

20=1/2×10×t^2 , 4=t^2 then t is 2 sec . when ball hit the ground it's velocity is v =? use 1st eqn of motion V=u+at , V= 10×2 then V is 20m/sec