The radius of a sphere is increasing at a rate of 2 mm/s. How fast is the volume increasing (in mm3/s) when the diameter is 100 mm

Answer :

Answer:

The radius is increasing at a rate of 62832 cubic millimeters per second when the diameter is of 100 mm.

Step-by-step explanation:

Volume of a sphere:

The volume of a sphere of radius r is given by:

[tex]V = \frac{4\pi r^3}{3}[/tex]

How fast is the volume increasing:

To find this, we have to differentiate the variables of the problem, which are V and r, implicitly in function of time. So

[tex]\frac{dV}{dt} = 4\pi r^2\frac{dr}{dt}[/tex]

The radius of a sphere is increasing at a rate of 2 mm/s.

This means that [tex]\frac{dr}{dt} = 2[/tex]

How fast is the volume increasing (in mm3/s) when the diameter is 100 mm?

Radius is half the diameter, so [tex]r = \frac{100}{2} = 50[/tex]

Then

[tex]\frac{dV}{dt} = 4\pi r^2\frac{dr}{dt} = 4\pi (50)^2(2) = 62832[/tex]

The radius is increasing at a rate of 62832 cubic millimeters per second when the diameter is of 100 mm.