Forces

This week we learned about forces... we've moved on from kinematics! (Cue applause here.) We learned that a force is defined as a push or pull. There are two kinds of forces— contact forces, and 'at a distance' forces. Contact forces are caused by contact between 2 objects. You might be thinking, "So these objects are moving." WRONG! Not necessarily. Contact forces don't necessarily cause movement. In fact, contact forces could be just as simple as me and my friend putting our arms around each other for a picture, like in the photo above. 'At a distance' forces are forces that push and pull on objects without touching them. One of the most obvious of these forces is gravity. (SOMETHING FROM KINEMATICS— Gravity= 9.8 m/s2.) These are balanced forces. However, there are also unbalanced forces, also known as net forces. These forces are those that cause an acceleration of an object. A good example of this is when you push a bowling ball down a lane. We're going to be doing a lot with these forces— we'll be implementing them into Newton's First Law of Motion— objects in motion will tend to stay in motion unless acted upon by an outside, unbalanced, force. That's like when you push a person off a cliff and they continue to fall until a spaceship with a scoop net saves them and stops their fall.