October 29, 2012

The fancy science definition:  An object will remain at rest or move in a straight line at a constant speed unless it is acted upon by a force I wish gravity would stop pulling my hair down.

Part A) Your object isn’t going to move unless you (or something else) gives it some force to make it move Part B) If your object is moving, it will keep moving in a straight line at the same speed unless something causes it to change that speed

 Comes from the Greek word for activity  Cannot be created or destroyed  Neither can mass…that is why those chemical equations need to be balanced!  Measured in Joules (J)  You may be familiar with kilowatt-hours and kilocalories (both types of energy)  Can be transformed into different types of energy  What types of energy can we think of?????

 Types of energy: ThermalMagnetic ChemicalElastic ElectricalSound Electromagnetic (sun)Mechanical NuclearLuminous (light)

 Potential Energy:  Energy that is stored due to its position  Not moving  Kinetic Energy:  Energy that is has due to its motion  Any kind of moving

Definition: a push or pull Measure force in Newtons (N) Math Plug n Chug: Force = mass x acceleration A force has:  A size and direction

 Balanced Forces  Equal and opposite forces  The object won’t move  Unbalanced Forces  If one force is bigger than the other, the box will move in the direction of the bigger force  In other words, if the object is moving, the forces are unbalanced

 Contact force  When two objects are physically touching  If you push your book with your finger and it moves in the direction you push it, this is a contact force  Long Range Force  Looks like nothing is touching it, but a force is moving it  If you drop a ball, gravity is acting on the ball…but it looks as if nothing is physically touching the ball

 The bigger the object, the more gravity is has  More mass = more gravity  Gives weight to objects  Your weight is the measurement of gravity pulling down on you  If we were on the moon, you’d weigh less because the moon is smaller than the Earth.

 An object’s ability to stay at rest or keep moving with a constant velocity  (velocity is speed with a direction)  Example: 35 m/s North  Depends on the object’s mass  A lot of mass = a lot of inertia  A little bit of mass = not a lot of inertia

 Mass is the amount of stuff inside something  Measured in grams  Kilograms  Milligrams  Grams