A ball is thrown in vertically upward direction. It returns back to the same position in 2s. Then the maximum height achieved by the ball is ...... (Take g = 9.8 ms^(-2))

A ball is thrown in vertically upward direction. It returns back to th

1.	A ball is thrown in vertically upward direction. It returns back to the same position in 2s. Then the maximum height achieved by the ball is ...... (Take g = 9.8 ms^(-2))
Answer» `9.8m ` `14.7m` `4.9m` `19.6`m Solution :To REACH at maximum height a ball need t=1 s even at that POSITION v =0. From `v = v _(0) - g t, , v _(0) =g t` Now, SUPPOSE maximum height is h. `THEREFORE v ^(2) - v _(0) ^(2) = 2gh` ` therefore (0)^(2) - (g t) ^(2) = 2gh` `therefore h = ((g t ) ^(2))/( 2g ) = (g t ^(2))/( 2) = ( 9.8 xx (1)^(2))/( 2) = 4.9 m`