Ch4_LefflerM

**__Fun Fun (Fig)Newton Time: Chapter 4__** = Group Lab Wiki =  toc

11/14/11 - Summarize Lesson 1: A-D
**Method 4** 
 * What does Newton's first law state?
 * Newton’s first law states an object in motion/rest says in motion/rest, until a force of greater value acts upon it. (Unbalanced force)
 * What is Inertia?
 * Inertia is the tendency for an object to resist change in its velocity (state of motion) and it’s acceleration.
 * How do objects move/ how long will they continue?
 * In the absence of an unbalanced force an object will move forever in the same direction and speed. A force is not needed to keep an object in motion; it’s what stops an abject in motion (Ff).
 * What is the correlation between inertia and mass?
 * The more mass that you have, the more inertia you have. More inertia = Less ability to change (more force needed)
 * What is equilibrium, and how does it effect motion?
 * If you add another force (like a push) the object is no longer at an equilibrium, which means it is in motion. Fg=FN (they cancel each other out)

11/16/11 - Summarize Lesson 2: A-D
**Method 4**
 * What is a force and what types of forces are there?
 * A force is a push or pull upon an object, it happens when two objects interact with each other (when thy stop so do the forces)
 * Two types of forces
 * Contact forces (when objects are actually touching. Friction, tension, and Normal are all contact forces)
 * Action-at-a-Distance Forces (when two objects aren’t directly in contact with each other like Gravity, Electric, and Magnetic forces)
 * How are forces measured?
 * They are measured in Newton’s.
 * What’s the difference between weight and mass?
 * Weight (lb) is the force of gravity applied to mass (kg), mass is the same without gravity, and other planets.
 * What is the difference between sliding and static friction?
 * Sliding friction is when an object slides against another object, while static friction is when two objects are against each other but not moving in relation to them.
 * What is important to remember when drawing a FBD?
 * 1) Tension is always going away from the object (pull)
 * 2) Normal is perpendicular to the object
 * 3) Weight is always strait down
 * 4) Friction goes in the opposite direction of the movement
 * 5) The arrows are vectors so size matters
 * How do you determine net force?
 * 1) Look to see if there are opposing forces
 * 2) If there are subtract them
 * 3) IF the remainder is positive the new force is the remainder up (right), if it is negative then it is the remainder times -1 down (left).
 * 4) If there is no opposing force the net force is that number, and the direction of the vector.

11/17/11 - Summarize Lesson 3: A&B

 * What is Newton's Second law?
 * Newton states that acceleration is based on two separate things,
 * Un-balanced forces
 * Mass of object accelerating
 * more mass = less acceleration
 * more force = more acceleration






 * So what's the big misconception?
 * continuos motion = continuos force X
 * NO FORCE IS NEEDED TO KEEP A HORIZONTALLY MOVING OBJECT IN MOTION!!!
 * How do we get past the "big misconception"?
 * Don't study physics based on looks, So remember kids always use a calculator.