Suppose you were stranded on a desert island with only a convex lens and a mirror. Describe how you could use each of these tols to signal for help.
First, you could use the convex lens to start a fire by focusing sunlight onto some dry kindling or tinder. The reflection of sunlight through the lens will concentrate the heat onto a small point, eventually igniting the material and creating a visible signal of smoke.
Secondly, you could use the mirror to reflect sunlight towards any passing planes or boats. By angling the mirror in the direction of the potential rescuers, you can create a bright, flashing light that will catch their attention and signal your location.
By alternating between using the convex lens to create smoke signals and the mirror to create flashing light signals, you can increase your chances of being spotted and rescued. Remember to continuously scan the horizon and keep a lookout for any potential rescuers in order to maximize the effectiveness of your signals.