Question

CALCULUS RELATED RATES: A 20 foot ladder is leaning against a wall. The base of the ladder is placed 6 feet from the bottom of the wall. The base of the ladder slips away from the wall at a constant rate of 2 feet/sec. Find the velocity of the top of the ladder as it slider down the wall 3 seconds after it begins to fall.

Answer 1

Answer:

2.17ft/s

Step-by-step explanation:

Look at the sketch of ladder at the beginning and after 3 seconds it starts to fall,

Distance of ladder from the wall 3 seconds after ladder starts to fall                                       =  Initial distance+  Velocity× time

= 6 + 2×3

= 12ft

Use trignometry to find out the speed of the top of ladder

cosθ= 12/20

θ= 0.825 rad

tan θ= v/2

v= 2.17ft/s