Unit 5 More Newton

Today for unit five we reviewed Newton's three laws of physics. The first law is the Law of Inertia, that objects at rest (in motion) stay at rest (in motion) unless acted upon by an outside unbalanced force. The second law states that force equals mass times acceleration. The final law is that for every action there is an equal and opposite reaction. We use these laws to recognize the habits of an object's action and analyze it. For example these buildings are at rest and will remain at rest just like the first law says. Since they have a great mass it would take a lot of force, such as a devastating earthquake, to disturb their state of rest. This is how the second law explains the direct relationship between mass and force. However if the city were made of paper buildings (small mass) then a slight breeze could just as well disrupt the city. The buildings push down on the ground with a certain force and the ground pushes back with that equal force. If this did not happen, then the buildings would sink into the ground. This is like the third law because the buildings push down with a force, and the ground pushes back with an upward (opposite) force. These laws can also be represented in Free Body Diagrams. That is a diagram that illustrates what forces are present using vectors. This is a simple way to sketch the magnitude and direction of different forces such as tension, weight, and friction. These diagrams will come in handy when several forces are affecting an object.