A lighthouse is 1 mile from a perpendicular shore with a night light rotating at a rate of 6 revolutions per minute. How fast is the light beam moving down the shore line when it is 1 mile from the perpendicular?

Question

anonymous · Answer

the circumference of the circle of rotation is 2*pi*r = 2*pi miles. Since it rotates 6 times per minute, the speed is 2*pi/6 miles/minute

anonymous · Answer

or did i not understand the question

anonymous · Answer

The question is asking for the speed of the exact moment when the light beam is perpendicular to the shore line.