Ch4+LambertM

= = toc =__Chapter 4__=

Homework Assignment 1-Newtons Laws (a-d):Method 4
Survey Questions Read Recite and review
 * a) Newton's First Law**
 * 1) What is Newton's First Law?
 * 2) What are everyday applications of Newton's First Law?
 * 1) **Newton's First Law (law of inertia)**: An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
 * 2) **Everyday applications**: A person's body stays in motion when when a car brakes and stops.

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 * b) Inertia and Mass**
 * 1) What was Galileo's concept of inertia?
 * 2) Why don't forces keep objects moving?
 * 3) How is mass a measure of the amount of inertia?
 * 1) **Galileo's concept of inertia**: Moving objects eventually stop because of a force called friction.
 * 2) **Why forces don't keep objects moving**: An object in motion on a flat surface does not stop because of the absence of a force; but because of the presence of a force (friction). In the absence of friction, the object would continue in motion with the same speed and direction forever.
 * 3) **How mass is a measure of the amount of inertia**: The tendency of an object to resist changes in its state of motion varies with mass. The more inertia an object has, the more mass it has. A more massive object has a greater tendency to resist changes in its state of motion.

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 * c) State of Motion**
 * 1) What does the phrase "state of motion" mean?
 * 1) **An object's state of motion**: The state of motion of an object is defined by its velocity.
 * Inertia
 * The tendency of an object to resist changes in its velocity
 * The tendency of an object to resist accelerations

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 * d) Balanced and Unbalanced Forces**
 * 1) What are balanced and unbalanced forces?
 * 2) What is equilibrium?
 * 1) **Balanced and unbalanced forces**:
 * Balanced forces-forces acting upon an object that are of equal magnitude and in opposite directions
 * Unbalanced forces-forces acting upon an object that are __not__ of equal magnitude and are __not__ in opposite directions.
 * 1) **Equilibrium**: When there are no unbalanced forces acting upon an object and the object maintains its state of motion. It will not accelerate.

Homework Assignment 2-Force and Its Representation (a-d):Method 4
Survey Question Read Recite and review
 * a) The Meaning of Force**
 * 1) What is the meaning of force?
 * 2) What are contact forces?
 * 3) What are at-a-distance-forces?
 * 4) What is a Newton?
 * 1) **Meaning of force**: A force is a push or pull upon an object resulting from the object's //interaction// with another object. When the //interaction// ceases, the two objects no longer experience the force.
 * 2) **Contact forces**: Contact forces result when the two interacting objects are perceived to be physically contacting each other.
 * Examples: frictional forces, tensional forces, normal forces, air resistance forces, and applied forces.
 * 1) **At-a-distance-forces**: At-a-distance-forces result when the two interacting objects are not in physical contact with each other, but are able to exert a push or pull despite their physical separation.
 * Examples: gravitational forces, electrical forces, magnetic forces.
 * 1) **Newton**: A Newton is a standard metric union that measures force.
 * [[image:http://www.physicsclassroom.com/Class/newtlaws/u2l2a2.gif align="center" caption="external image u2l2a2.gif"]]

Survey Question Read Recite and review
 * b) Types of Forces**
 * 1) What are the different types of forces?
 * 2) What is the different between weight and mass?
 * 1) **Types of forces**:
 * Applied force - A force that is applied to an object by a person or another object.
 * Gravity force - The force with which the earth, moon, or other massively large object attracts another object towards itself; weight of the object.
 * Normal force - The support force exerted upon an object that is in contact with another stable object.
 * Friction force -The force exerted by a surface as an object moves across it or makes an effort to move across it.
 * Air resistance force - A special type of frictional force that acts upon objects as they travel through the air.
 * Tension force - The force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends.
 * Spring force - The force exerted by a compressed or stretched spring upon any object that is attached to it.
 * 1) **Mass vs. weight**: Weight is the force of gravity acting upon an object and mass is the amount of matter that is contained by the object.

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 * c) Drawing Free-Body Diagrams**
 * 1) What are free-body diagrams?
 * 2) How do you draw free-body diagrams?
 * 1) **Free-body diagrams**: Vector diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation.
 * 2) **How to draw free body diagrams**: The only //rule//for drawing free-body diagrams is to depict all the forces that exist for that object in the given situation
 * Identify which forces are present
 * Determine the direction in which each force is acting
 * Draw a box and add arrows for each existing force in the appropriate direction
 * Label each force arrow according to its type and if there are repeating forces make sure to alter the name in some way, example: T 1, T 2

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 * d) Determining the Net Force**
 * 1) What is net force, and how do you determine an object's net force?
 * 2) How do you determine an object's net force?
 * 1) **Net force**: Net force is the vector sum of all the forces that act upon an object and is determined by finding this sum.
 * Net force takes into account the fact that a force is a vector and two forces of equal magnitude and opposite direction will cancel each other out

Homework Assignment 3-Newton's Second Law of Motion (a, b):Method 4
Survey Question Read Recite and review
 * a) Newton's Second Law**
 * 1) What is Newton's Second Law of Motion?
 * 2) What equation is used for Newton's Second Law?
 * 1) **Newton's Second Law**: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object
 * 2) F net = mas*acceleration

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 * b) The Big Misconception**
 * 1) What is the big misconception?
 * 1) ****The Big Misconception:**** The idea that sustaining motion requires a continued force
 * Newton's laws declare loudly that a net force (an unbalanced force) causes an acceleration; the acceleration is in the same direction as the net force