Posted by sara on Tuesday, October 16, 2012 at 2:53am.
same question ....
http://www.jiskha.com/display.cgi?id=1333489636
just change the necessary numbers
since you have a calculus class, you probably ought to do it Reiny's way, but sometimes a little simplification can save you some work:
If the man is x away from pole, ad his shadow length is s, then using similar triangles,
s/2 = (x+s)/6
s = 1/2 x
so, ds/dt = 1/2 dx/dt
since the tip of the shadow is x+s from the pole, it is moving at
dx/dt + ds/dt = dx/dt + 1/2 dx/dt = 3/2 dx/dt = 3/2(1.4) = 2.1 m/s
Related Questions
calculus - A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft...
Math - A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft ...
Calculus - A street light is at the top of a 19 foot tall pole. A 6 foot tall ...
Calculus - A street light is at the top of a 17 ft tall pole. A woman 6 ft tall ...
calculus - A street light is at the top of a 13 ft tall pole. A woman 6 ft tall ...
calculus - A street light is at the top of a 20 ft tall pole. A woman 6 ft tall ...
calculus - A street light is at the top of a 16 ft tall pole. A woman 6 ft tall...
calculus - A street light is at the top of a 15 ft tall pole. A woman 6 ft tall ...
calculus - A street light is at the top of a 16 ft tall pole. A woman 6 ft tall...
Calculus 1 - A street light is at the top of a 19 ft tall pole. A woman 6 ft ...
For Further Reading
