Thursday

November 20, 2014

November 20, 2014

Posted by **bryan** on Sunday, February 3, 2013 at 11:47am.

- Calculus -
**Reiny**, Sunday, February 3, 2013 at 12:09pmmake a sketch, place the man x m from the light

let the length of the shadow on the wall me y m

by similar triangles : 2/x = y/12

xy = 24

x dy/dt + y dx/dt = 0

dy/dt = -y dx/dt / x

when he is 4 m from the wall x = 8 (look at our diagram)

so in xy=24 --> 8y = 24 or y = 3

and dx/dt = 1.6

dy/dt = -3(1.6)/8

= - .6 m

at that moment his shadow is decreasing at .6 m /s

**Answer this Question**

**Related Questions**

calculus - a spotlight on the ground shines on a wall 12 m away. if a man 2m ...

Calculus - A spotlight on the ground shines on a wall 12 m away. If a man 2 m ...

Calculus - If any body can solve this I would be greatly appreciative. I spent ...

Calculus - A spotlight on the ground is shining on a wall 12m away. If a woman ...

Calculus - Answers to any of these questions would be of great help! (: 1 a) At ...

Calculus - Answers to any of these questions would be of great help! (: 1 a) At ...

math HELP plz - Richard is standing between two buildings in a townhouse ...

math - Richard is standing between two buildings in a town house development.The...

math - Richard is standing between two buildings in a town house development.The...

Math - Richard is standing between two buildings in a townhouse development. The...