Featured Deals:
Path Lights Set
how to set up this related rates problem?
A street light is mounted at the top of a 15 foot tall pole. A man 6 ft tall walks away from the pole with a speed of 4 ft/s along a straight path. How fast is the tip of his shadow moving when he is 40 ft from the pole?
Draw a picture, choose suitable coordinates and units, choose variables, if it don't look pretty rethink some alternatives...
Light L is @ (0,15)
Man's head H is @ (4t, 6)
Tip of shadow T will be @ y=0 in a straight line going from L through H.
(x1,y1) = L (0,15)
(x2,y2) = H (4t, 6)
Hence, eqn of line is:
(y-15)/(6-15) = (x-0)/(4t-0)
To find T, we only ever care about the y=0 solution:
-15/(6-15) = x/4t
x = 4t*15/9 = 20t/3
So tip of shadow T is located at (20t/3, 0)
>How fast is the tip of his shadow moving when he is 40 ft from the pole?
T is only moving horizontally.
dxT(t)/dt = 20/3 ft/s (constant, and we didn't need to know =40. So I may have made a mistake but you get the approach.)
Current EBay auctions for Path Lights Set
4 Pack Motion Sensor Stainless Steel Outdoor
Solar Path Light Set, NEW Target Home
Solar Path Light Set Black Finish Set of 4, NEW Target Home
Solar Path Light Set Stainless Steel Finish Set of 4, Set of 2 Color Changing
Solar Powered Garden Path Light, Stampin Up A Light Unto My Path Retired WM Set of 2, Tabletop
Solar Lantern Set 2Pk Bronze Outside Path Light Garden Landscaping, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Garden Path Light Stainless Steel Set of 6, Strathwood
Solar Garden Path Light Stainless Steel Set of 6, NEW Strathwood
Solar Path Lights Stainless Steel Set of 10,
SOLAR PAGODA LIGHTPATH LIGHTING SET OF 6 FREE SHIP, NEW Strathwood
Solar Path Lights Stainless Steel Set of 10, NEW Strathwood
Solar Path Lights Stainless Steel Set of 10, NEW Strathwood
Solar Path Lights Stainless Steel Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Strathwood
Solar Path Lights Copper Set of 10, Home and Garden Blue
Solar Bell Path Lights Set of 3, Set of 4 Outdoor
Solar Powered Garden Lawn Path Lights, NEW Target Home
Solar Path Light Set Antique Copper Finish Set of 4, 10 Piece Stainless Steel
Solar Light Set Path Lighting, PORTFOLIO 6 Light Low Voltage Path Light Set COPPER, Set of 2 NUVO Satco 76 637 10 Path Light Three Louver Large Hood Old Bronze, Set of 4
Solar Garden Lily Lights Path Light, Set of 4
Solar Garden Rose Lights Path Light, Set of 2 Stainless Steel Cone
Solar Garden Path Lights,
Tags:
lights,
path,
shopping,
solar,
wedding
Related posts
