Question # A body is thrown up in a lift with a velocity u relative to the lift and the time of flight is found to be ( t ). The

# A body is thrown up in a lift with a velocity u relative to the lift and the time of flight is found to be ( t ). The

acceleration with which the lift is moving up is

(A) ( frac{u-g t}{t} )

(B) ( frac{2 u-g t}{t} )

(C) ( frac{u+B !}{t} )

(D) ( frac{2 u+p t}{t} )

Solution

( T_{f}=frac{2 u}{g^{prime}} Rightarrow g^{prime}=frac{2 u}{t} Rightarrow g+a=frac{2 u}{t} )

( Rightarrow a=frac{2 u}{t}-g )