A lens forms a real image that is 214 cm away from the object and 12 3 times its height. What kind of lens is this, and what is its focal length?
Goals • To learn why a light wave contains both electric and magnetic fields • To relate the speed of light to the fundamental constants of electromagnetism • To describe electromagnetic waves • To determine the power carried by electromagnetic waves • To describe standing electromagnetic waves Introduction • Why do metals reflect light • We will see that light is an electromagnetic wave. • There are many other examples of electromagnetic waves, such as radiowaves and x rays. Unlike sound or waves on a string, these waves do not require a medium to travel. Maxwell’s equations and electromagnetic waves • Maxwell’s equations predicted that an oscillating charge emits electromagnetic radiation in the form of electromagnetic wa