Question # From a building two balls ( A ) and ( B ) are thrown such that ( A ) is thrown upwards ( A ) and ( B ) downwards (both vertically). If ( mathrm{V}_{mathrm{A}} ) and ( mathrm{V}_{mathrm{B}} ) are their respective velocities on reaching the ground, then ( quad )

# From a building two balls ( A ) and ( B ) are thrown such that ( A ) is thrown upwards ( A ) and ( B ) downwards (both vertically). If ( mathrm{V}_{mathrm{A}} ) and ( mathrm{V}_{mathrm{B}} ) are their respective velocities on reaching the ground, then ( quad )

( (A) V_{B}>V_{A} )

(B) ( V_{A}=V_{B} )

(C) ( V_{A}>V_{B} )

(D) their velocities depend on their masses

Solution

Using the concentration of energy the

ie PE = at height h equals K.E at ground.

[

begin{array}{c}

Rightarrow m_{A} g h=left(m_{A} v_{A}^{2}right) / 2

V_{A}=sqrt{2} g h

end{array}

]

Smnilelly

[

V_{B}=sqrt{2} g h

]

[

V A=V B

]