A powerful storm is approaching. The weather forecast calls for gale-force winds. Many people in the city decide to leave work early in order to get home before things get worse. As shown in Figure 1, a man pushes ahead into a strong wind and shields himself from the driving rain with an umbrella. The strong wind makes it very difficult for him to hold onto his umbrella. To keep the umbrella from being pulled from his hands, he tightly squeezes the umbrella handle. Elsewhere, a store owner attempts to bring in a folding sign that hasn't blown away because it is chained to a pole.

Figure 1  The wind pushes against the man and his umbrella. The push from the wind is a force.

Wind is but one example of the many forces you experience every day. The study of forces is a very important part of physics. As you read this section you'll learn what forces are and how they make things move.