September 19 Jennifer Blazejack

Introduction
Physics
Motion (formulas)
Mass and Weight
Laws of Motion
Conservation Laws
Energy Types
Conclusion
Introduction
We took a quiz and were given a slide show on Physics. 
Physics
“The study of motion” can seem “boring and uninteresting”, but the question of how the world exists is actually a scientific question. There is a book that can help explain that question. Newton, Galileo, Kepler, and Brahe also wrote books to explain the world around them. 
Motion (formulas)
There are three important parts in motion: speed, velocity, and acceleration.

Speed: rate at which object moves

Speed= distance

time

Velocity: speed and direction

V= 2Пr

     T

Acceleration: any change in velocity; units of speed/time

A=2Пr

   T

(There are many other important formulas that are listed in the blog)
Momentum is mass×velocity and force is the way to change an object’s momentum. Rotational momentum is important to remember because it’s relative to the Sun. If an object goes away from the Sun then it goes away in that direction (which is bad) and if an object gets too close to the Sun (which is very bad) its burns so the best way to avoid flying away or burning is to rotate around the Sun at a safe distance (which is why Earth is a pleasant place to live). 


Mass and Weight
Mass is matter (which is constant) and weight involves gravity.  When an astronaut is weightless he is floating because he is falling at the same rate as the Moon or Earth. A good example of this (involving acceleration) is a person in an elevator. When the string breaks on the elevator then the person “floats” inside, but in reality they are falling relative to the Earth and not each other. Weightlessness just means an object is in constant free fall. 
Laws of Motion
Elbert Einstein eventually proved Newton wrong in some parts of the laws, but the laws are still important.

Newton’s Laws of Motion

1) An object at rest stays at rest and an object in motion stays in motion (unless they are affected by an outside force).
2) The amount of acceleration depends on the object’s mass and net force strength (f=ma)
3) There is an equal and opposite reaction force
Conservation Laws
Conservation of angular momentum: the total angular momentum can never change—it can only change its angular momentum by transferring some angular momentum to or from another object
Conservation of energy: energy cannot appear or disappear out of nothing—objects can only gain or lose energy by exchanging energy with another object
Conservation of momentum: the total momentum of all interacting objects always stays the same
Energy Types
Kinetic: energy of motion
Radioactive: energy carried by light
Potential: stored energy
Thermal: collective kinetic energy of the many individual particles moving randomly in a substance

• Thermal energy is not the same as temperature. Temperature measures the average kinetic energy of the particles

Gravitational potential: depends on its mass and how far it can fall as a result of gravity
Mass-Energy: mass has a form of potential energy

• E=mc2

Conclusion
We were told that we will have a PowerPoint presentation due at the end of the semester (5-10 minutes long) and to choose our topic for the 5 page term paper due in November as well.