Performance Indicator 5.1
"Describe different patterns of motion of objects."

1. The motion of an object is related (judged) to that of another object. When you watch TV you believe that you are sitting still. Aren't you? Well, you are actually rotating with the earth. If your were not moving with the earth you would have it moving underneath you. Think of it as riding in a car. The earth is the car you are riding on. Frame of reference is the fixed object we use to help base our motion. Were you ever in your parents car stopped at a light. At the car next to you moved forward and you thought you were moving backwards? You were using the other car as your frame of reference. Here is another example. Where is the moon? Up in the sky right. We are using the Earth as our frame of reference. But what happens when you are on the moon? Is the earth below us? No, if we look down when we are at the moon we would be looking at the surface of the moon. Instead we must look up to see the earth. The moon is now our frame of reference.
2. The motion of any object can be described by its position, direction of motion, and speed. An objects speed and direction is called velocity.
3. Newtons Laws of Motion:

• Newtons 1st law of motion states that an object will continue its motion until an outside force acts upon it. This can be refered to as inertia. The ablity of an object to keep doing what it is already doing. An object at rest will stay at rest and an object in motion will stay in motion.
  If you leave your books on the table over night and retuen in the morning tyou will find your books exactly where you left them. They were at rest and stayed that way all night long. they will continue to stay like that until someone uses a force to move them.
  If you were to slide a puck along the ice it continues for a long period of time. The puck would continue on for ever if gravity would not be pulling down on the puck and friction between the puck and the ice slowing down the motion of the puck. In outer space objects will continue in a straight line until an outside force acts on them.
  
• Newtons 2nd Law states that an onject will move in the direction an unbalanced force points. We can do this by using the formula: F= M x A. Force equals Mass times Acceleration. The greater the force applied to the object the greater the change in motion.
  
• Newtons 3rd Law of motion states for every action there is an equal and opposite reaction. The best example is when you are swimming or rowing a boat. You push the water behind you in order to move forward. Rocket ships use this same priciple to move through outer space. They use hot expanding gases to manuver themselves through space. If they want to move forward they push the gas in the opposite direction. If they want to slow down they will reverse the direction of there thrusters.
  

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