Rate problem

[tandoorichicken]

Its been a while since I did something like this:

A man 6 ft tall walks at the rate of 5 ft/sec toward a street light that is 16 ft above the ground. At what rate is the length of his shadow changing when he is 10 ft from the base of the light?

And I forgot how.
Please help. Thx.

[himanshu121]

http://physicsforums.com/showthread.php?s=&threadid=10792

The above link will help this is the same kind of Problem