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.