Rate of Change of Volume of Sphere w/ Radius Expanding at 50 cm/min

[sammiyahc0]

1. Assume that the radius r of a sphere is expanding at a rate of 50 cm/min. The volume of a sphere is V= 4/3 πr^3 and its surface area is 4πr^2.Determine the rate of change of volume when r = 13 cm



2. I tried d/dr=8*13*50*pi



3. 5200pi but is wrong

 

[haruspex]

Pls post your reasoning/working to obtain that expression for (I presume you meant) dV/dr.