SOLUTION: A man 6 feet tall walks away from light 10 feet above the ground. If his shadow lengthens at a rate of 2 feet per second, how fast is he walking? Please give details Thank y

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Question 991365: A man 6 feet tall walks away from light 10 feet above the ground. If his shadow lengthens at a rate of 2 feet per second, how fast is he walking?

Please give details
Thank you
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Start with a right triangle.
Form similar triangles with height 10 and height 6.
The horizontal distance from the light to the man is a.
The horizontal distance from the man to the tip of the shadow is b.
So then,
10%2F6=%28a%2Bb%29%2Fb
10b=6a%2B6b
4b=6a
2b=3a
2%28db%2Fdt%29=3%28da%2Fdt%29
2%282%29=3%28da%2Fdt%29
da%2Fdt=4%2F3fps