Making the Universe

Making the Universe 

Notes from September 19th, 2012 

Motion 

Speed- how far something will go in a certain amount of time 

Velocity- Both the speed and direction of an object 

Acceleration- velocity is changing in any way, whether in speed or direction, or both 

Acceleration of Gravity- Galileo demonstrated that gravity accelerates all objects by the same amount, regardless of their mass (air resistance- causes differences in acceleration. 

Momentum and Force- momentum is mass x velocity. The only way to change an objects momentum is to apply a force to it. Rotational momentum of a spinning or orbiting object is known as angular momentum. Mass is different than weight in that mass is the amount of matter in your body. Weight (apparent weight) is the force that a scale measures when you stand on it, weight depends both on your mass and the force acting upon you. Earth is always falling in respect to the Sun. Free fall is falling without any resistance to slow you down (weightless). 

Newton's Law of Motion 

Newton saw the apple fall to the ground and realized the heavens have gravity just like Earth. Newton began science of astrophysics which applies physical laws discovered on Earth to phenomenal throughout cosmos. 

Newton's Laws: 

1) An object moves at constant velocity if there is no net force acting upon it. 

2) Force = mass x acceleration 

3) For any force, there is always an equal and opposite reaction force (action/reaction) 

Laws of Physics are decided by physicists, new laws change when new knowledge is available. Predictors when validated by observation are the only condition.