# A ball is thrown vertically upwards. It was observed at a height ℎ twice with a time interval ∆𝑡. The initial velocity of the ball is

Question : A ball is thrown vertically upwards. It was observed at a height ℎ twice with a time interval ∆𝑡. The initial velocity of the ball is

(A) $\sqrt{8gh+g^{2}\left( \Delta t\right) ^{2}}$

(B) $\sqrt{8gn+\left( \dfrac{g\Delta t}{2}\right) ^{2}}$

(C) $\dfrac{1}{2}\sqrt{8gh+g^{2}\left( \Delta t\right) ^{2}}$

(D) $\sqrt{8gh+4g^{2}\left( \Delta t^{2}\right) }$