If a Cylindrical Tank Holds 10000 Gallons of Water, Which $t$

If a cylindrical tank holds 10000 gallons of water, which can be drained from the bottom of the tank in an hour, then Torricelli's Law gives the volume of water remaining in the tank after $t$ minutes as
$V ( t ) = 10000 \left( 1 - \frac { 1 } { 60 } t \right) ^ { 2 } , 0 \leq t \leq 60$
Find the rate at which the water is flowing out of the tank (the instantaneous rate of change of $V$ with respect to $t$ ) as a function of $t$ .