In Physics, we distinguish between wave motion and particle motion. Wave motion refers to the movement of a wave-like pattern from one location on the medium to another. When you view a water wave moving along the surface of water, you are observing wave motion. There is a very obvious movement of a collection of crests and troughs along the water surface. In the Simple Wave Simulator, there is a collection of crests and troughs moving through a rope; this is wave motion. But there are also three points on the rope that are colored red. When you observe the motion of these points, you are observing particle motion - the motion of particles of the rope. Describe the motion of these particles.

You are the coordinator for a program that is going to take place at night in a rectangular amphitheater in the mountains. you will have no access to any electricity, but you must be able to illuminate the entire grounds. you know the intensity of the light from a lantern varies inversely as the square of the distance from the lantern. suppose the intensity is 90 when the distance is 5 m. a. write an equation to model the situation. b. solve for the constant of variation. c. write the equation to model the situation using the constant () of variation. d. you have been given lanterns with 40 light intensity. use your equation to solve for the distance from the lantern. e. you need to illuminate 225 km. how many meters do you need to light? f. how many lanterns will you need?