Related rates problem:

The beacon on a lighthouse makes one revolution every 20 seconds. The beacon is 300 feet from the nearest point, P, on a straight shoreline. Find the rate at which the ray of light moves along the shore at a point 200 feet from P. (In other words, how fast would you have to drive a car along the shoreline so that you keep up with the light constantly if you were 200 feet from P on the shoreline).

Question

Related rates problem:

The beacon on a lighthouse makes one revolution every 20 seconds.  The beacon is 300 feet from the nearest point, P, on a straight shoreline.  Find the rate at which the ray of light moves along the shore at a point 200 feet from P. (In other words, how fast would you have to drive a car along the shoreline so that you keep up with the light constantly if you were 200 feet from P on the shoreline).

anonymous · Answer

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anonymous · Answer

tan(T) = 200/300
dT/dt = pi/10 radians per second

anonymous · Answer

10 = (300(dx/dt) - 200(dy/dt))/(300^2) , do these look correct so far?

anonymous · Answer

http://www.jiskha.com/display.cgi?id=1339826996 for those interested