A large spherical snowball melts such that its volume decreases at a rate of 4.5 cm3/min. Determine the rate of decrease of the radius when the radius is 7 cm.
v = 4/3 πr^3
dv/dt = 4πr^2 dr/dt
now just plug in your numbers and find dr/dt
dv/dt = 4πr^2 dr/dt
now just plug in your numbers and find dr/dt