8. Sand pours from a chute and forms a conical pile whose height is always 2 times the base radius. If the base radius of the pile increases at a rate of 7 feet/hour, find the rate of change of the volume of the conic pile, when the base diameter of the pile is 10 feet.

Question

8.	Sand pours from a chute and forms a conical pile whose height is always 2 times the base radius. If the base radius of the pile increases at a rate of 7 feet/hour, find the rate of change of the volume of the conic pile, when the base diameter of the pile is 10 feet.

anonymous · Answer

wait for a while. i'm solving it.

anonymous · Answer

$$V=1/3\pi r ^{2}h$$
$$dv/dt=1/3\pi rdr/dt (2)h$$
$$dv/dt=2/3\pi r dr/dt  h$$
r=5,h=10, dr/dt=7ft/hr.
$$dV/dt=(700\pi)/3$$

anonymous · Answer

the unit is feet per hour.

anonymous · Answer

i hope this can help.