Question

A street light is mounted at the top of a 14 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 6 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 45 ft from the base of the pole?

Answer 1

use similar triangles. create two similar triangles based on the information tehn take the derivative

Answer 2

i dont understand how to do that

Answer 3

check out this website and go to example 2, it has a similar question with different numbers =) http://www.math.wfu.edu/tutorials/Math111/RelatedRates.pdf

Answer 4

okay carra i will solve it, im done with my hw

Answer 5

For the answer try 9/2 (ft/sec) , let me know whether it is correct. If it is, I will post the solution.

Answer 6

no not the answer

Answer 7

try 4.5

Answer 8

no

Answer 9

k let me see if i did anythinig wrong, brb

Answer 10

can you double check the question?

Answer 11

question is correct

Answer 12

okay, let me check my work again

Answer 13

can you try 4/3 or 1.3

Answer 14

no i sorry

Answer 15

hey

Answer 16

im on the case

Answer 17

do you mind, i will use twiddla

Answer 18

http://www.twiddla.com/492533

Answer 19

click on that

Answer 20

Okay so cantorset, this is what im doing:
y/6 = (y+x)/14 => look at that in terms of similar triangles.
Cross multiply and simplify:
14y = 6x + 6y
14(dy/dt)=6(dx/dt) + 6(dy/dt)
8 d(y/dt) = 6 (dx/dt)
8(dy/dt) = 6 * 6
8(dy/dt) = 36, solve for dy/dt = 9/2. What am I doing wrong?

Answer 21

its a whiteboard

Answer 22

carra try 10.5

Answer 23

uploading the screen

Answer 24

http://i53.tinypic.com/o6i8b7.jpg
there's the screen

Answer 25

i gtg now, bbl