Homework Help: calculus

Posted by Anonymous on Wednesday, January 5, 2011 at 9:05pm.

a rectangular room is 20 ft by 12 ft by 8 ft. If the length is decreasing by 4 inches per minute, the width is decreasing by 5 inches per minute and the height remains constant, how fast is the volume changing after 2 minutes?

calculus - Reiny, Wednesday, January 5, 2011 at 10:52pm
let the width be x
let the length be y
let the height be h

V= xyh
dV/dt = xy dh/dt + xh dy/dt + yh dx/dt

given x=20, y=12, h = 8
dx/dt = 5
dy/dt = -4
dh/dt = 0

Plug in those values into dV/dt

Answer this Question

Related Questions

math - find the volume of a tent having the shape of a rectangular solid of ...
Math - An architect designed a rectangular room with an area of 925 square feet...
calc - can you just show me how to set this up? or a formula that could help? im...
geomery b - I need help understanding this so please help me?? 1. A table is 4 ...
algebra - Direct and Joint Variation 2. The volume V of a rectangular prism of a...
math - Direct and Joint Variation 2. The volume V of a rectangular prism of a ...
Math - A rectangular field is to be enclosed with 1270 ft of fencing. If the ...
math - A rectangular field is to be enclosed with 1130 ft of fencing. If the ...
Math - What would the surface area be for a rectangular prism that has a height ...
algebra - Martha is having carpet installed in a rectangular room.She estimates ...

For Further Reading

First Name:
School Subject:
Answer: