Question

If the radius of a sphere is increasing at a constant rate of 4 cm/sec, then the volume is increasing at a rate of ???? cm^3/sec when the radius is 5 cm.

Answer 1

v = 4/3 pi r^3
dv/dt = 4 pi r^2 dr/dt

now just plug in your numbers ...

Answer 2

I got 264586.8
by calculating

268.08x 986.96

where did I go wrong?

Thanks steve

Answer 3

where ever did you get those numbers?

4 pi r^2 dr/dt
= 4 * pi * 5^2 * 4
= 400 pi cm^3/s