What are 5 human tools that utilize the properties of straight propagating light?
Light will propagate in a straight line if it passes through an intermediary medium, you can see that when sunlight enters our house through a window it will appear in the form of straight lines. Another example is the flame of a flashlight which propagates in a straight line. If the light that can propagate in a straight line is used to make human equipment such as film projectors, OHP, cameras, flashlights, and motorbike lights.