333 physics - unit 2 explanations as to why things occur versus just observation
TRANSCRIPT
Copernicus & the moving EarthWhat idea did Copernicus propose that revolutionize science?
What view was held prior to Copernicus proposal?
In the year 1642, Galileo died and Issac Newton was born. He was a genius who essentially wrote the book of physics in 18months.He furthered Galileo’s idea and generated Newton’s Laws of Motion.
Law of INERTIA OR 1ST LAW:• Objects tend to ______________________________
• Objects tend to ______________________________
• Object at rest ________________________________
• Unless object is acted on by a FORCE along the path of motion ____________________________
A force is a ____________________
A Newton is the unit of force (N)
Mass
Mass is not weight.
You can change your weight without changing your mass. How?
• Mass is the measure _____________ •Mass is measured in kilograms (kg).
• Mass is something _________________
An argument against a moving Earth (Copernicus) was the following:
Consider a bird sitting at rest at the top of a tall tree. If the earth is really moving around the sun at 30km/s and also rotating at 1000mph, then how does a bird dive down to catch a worm?
Why doesn’t classroom wall hit us if we jump up in air?
3rd LAW or Action/Reaction
• For every ACTION FORCE• This is due to an interaction between 2 objects.• Forces occur in pairs!
Forces occur in pairs. Action-reaction pairs do NOT cancel one another out…WHY?
Walking or Jumping Swimming
Ducks fly in a V formation because air pushed downward at the tips of their wings swirls upward, creating an updraft that is strongest off to the side of the bird. A trailing bird gets added lift by positioning itself in this updraft, pushes air downward, and creates another updraft for the next bird, and so on. The result is a flock flying in a V formation.
Question: A loaded school bus hits a bug and kills it. Which body receives the greater force of impact, bug or bus?