# related rates

1. ### Lesson Related Rates: Lighthouse Beam

A lighthouse is fixed $$y$$ units from a straight shoreline. A spotlight in the lighthouse revolves at a rate of $$R$$ revolutions per minute, shining a spot along the shoreline as it spins. At what rate is the spot moving when it is along the shoreline $$x$$ units from the shoreline point...
2. ### Lesson Related Rates: A Sand Pile

Sand is being dumped from a conveyor belt at a constant rate, forming a conical pile. The ratio of the base radius of this pile to its height is constant. Find the height of the pile as a function of time. To begin this problem, let's define some constants: $$a$$ = the rate at which sand is...