Forces and the Laws of Motion: Introduction You are probably sitting at a computer as you read this. In order to navigate to this page, you might press keys on a keyboard or you might slide a mouse around on a mouse pad. Each of these movements involves forces. Your fingers exert forces on the keys of your keyboard or your computer’s mouse.
In this unit you will learn about forces. You will learn that the motion of an object depends on the combination of the different forces. The resultant force is one force that has the same effect as the sum of all the forces on an object. Force is a vector quantity; it has both magnitude and direction.
This is definitely a section where practice makes perfect. You'll need to work many problems until you're comfortable with all of the techniques. It will also help you to draw diagrams, called free-body diagrams, so you can see what's happening and see if your results are reasonable. 