Calc to Physical World Q... (1 Viewer)

[switchblade87]

If you can answer this showing working, that would be helpful.

The volume of a cylinder is given by V = pi.r².h m³.
(a) Find the formula for the rate of change in the volume with respect to changes in the radius where the height is kept constant.
(b) What is the exact rate of change in volume of a cylinder with height 8m, where the radius is 10m?

Answers:
(a) dV/dR = 2.pi.r.h m³ per m
(b) 160.pi m³ per m

Cheers

 

[acmilan]

(a) just differentiate with respect to r

V = pi.r².h
dV/dr = 2pi.r.h

(b) sub in r = 10 and h = 8 to dV/dr

 

[switchblade87]

(a) just differentiate with respect to r

V = pi.r².h
dV/dr = 2pi.r.h

(b) sub in r = 10 and h = 8 to dV/dr

Well, you made me look stupid on (a), thats so simple I can't believe it. That makes (b) easy too, thanks acmilan. (btw, GO INTER)