Posted by **chris** on Monday, December 8, 2008 at 4:10pm.

a 20m ladder rests vertically against the side of a barn. a pig that has been hitched to the ladder starts to pull the base of the ladder away from the wall at a constant rate of 40 cm per second. find the rate of change of the height of the top of the ladder after 30 secs

- calculus helpppp! -
**bobpursley**, Monday, December 8, 2008 at 4:40pm
Using Pythagorean theorm,

length^2=b^2+ h^2

where b is the base length, and h is the height.

Taking the derivative..

0=2b db/dt + 2h dh/dt

you are given db/dt, solve for dh/dt

For the second part, you will have to find b and h at 30 sec. b will be .40*30, solve for h, and again, you have it.

## Answer This Question

## Related Questions

- Calculus - Suppose a ladder of length 36 feet rests against a wall, and we pull ...
- phsics - uniform ladder 25 ft long rests against a smooth vertical wall. The ...
- Calculus - a 5m ladder rests against a vertical wall. The top of the ladder ...
- Math 2 - The bottom of the ladder rests on a horizontal flat surface and the top...
- Calculus Ladder Problem - A ladder 20 ft long rests against a vertical wall. Let...
- Calculus 1 - A ladder 10ft long rests against a vertical wall. If the bottom on ...
- Calculus 1 - Related Rates: A ladder 10 ft long rests against a vertical wall. ...
- Calculus - A ladder 10 ft long rests against a vertical wall. If the bottom on ...
- Physics - A ladder ABC of length 20m is leaning against a wall at an angle from ...
- calculus - A 15-ft ladder rests against a vertical wall. If the top of the ...

More Related Questions