Posted by Michael on Thursday, December 2, 2010 at 10:08pm.
A ladder 10 ft long rests against a vertical wall. If the bottom of the ladder slides away from the wall at a rate of 2 ft/s, how fast is the angle between the ladder and the ground changing when the bottom of the ladder is 5 ft from the wall? Evaluate your answer numerically. (Round the answer to three decimal places.)

Related Rates  bobpursley, Thursday, December 2, 2010 at 10:16pm
let x be the horizontal distance from wall to ladder.
cosineTheta=x/10
10 cosTheta=x
10sinTheta dTheta/dt= dx/dt
so you are looking for dTheta/dt
when x=5, theta = arccos.5, or 60 deg, and sin of 50 = .877
dTheta/dt= dx/dt / (10*.877)
check all that. 
Related Rates  Jen, Sunday, October 11, 2015 at 1:14pm
.228