Example 3.5.3 of Active Calculus that I thought you'd like to know about. The units for the rates are not consistent: the first rate found, dr/dt, is measured in ft/sec, while the given rate, dV/dt, is measured in ft^3/min and that last rate found, dh/dt, is measured in ft/min. https://activecalculus.org/single/sec-3-5-rel-rates.html#SLC. (the one error is near the very end when dr/dt is reported.
Example 3.5.3 of Active Calculus that I thought you'd like to know about. The units for the rates are not consistent: the first rate found, dr/dt, is measured in ft/sec, while the given rate, dV/dt, is measured in ft^3/min and that last rate found, dh/dt, is measured in ft/min. https://activecalculus.org/single/sec-3-5-rel-rates.html#SLC. (the one error is near the very end when dr/dt is reported.