Ch4_FavaA

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=Lesson 1 - Newton's First Law of Motion= >>
 * 1) What is Newton's First Law?
 * "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"
 * objects will continue to move as they are moving
 * if you have an object inside of something and that thing is acted upon by unbalanced force, the object will continue forward
 * [[image:http://www.physicsclassroom.com/Class/newtlaws/u2l1a1.gif width="296" height="220" align="bottom"]]
 * 1) What exactly are inertia and mass?
 * inertia is an object's resistance to change in their state of motion
 * an object is naturally in motion and a force is needed to make it stop
 * tendency of an object to resist change varies with different masses
 * mass is dependent on inertia; more inertia = more mass
 * inertia is also tendency to resist accelerations
 * 1) What does "state of motion" mean?
 * state of motion is defined by velocity (speed with direction)
 * state of motion can only be changed by an unbalanced force
 * 1) What are balanced and unbalanced forces?
 * balanced forces are at equilibrium and are in opposite directions with equal magnitude; no acceleration
 * note: a force is not needed to keep a moving object movie
 * unbalanced forces are not at equilibrium and there isn't an equal force to contradict the other; there is acceleration
 * to figure out if forces are balanced/unbalanced, check to see if there is a force of equal magnitude going in opposite direction of another force

=Lesson 2 - Force and Its Representation=
 * 1) What is the meaning of force?
 * push or pull of an object resulting from interaction with another object
 * only exist as result of interaction, when interaction stops so does force
 * force is a vector quantity measured in Newtons
 * 1 N = 1 kg(m/s/s)
 * can cancel each other out and then known as balanced forces
 * 1) What are the types of forces?
 * contact forces - forces when two objects are in contact
 * frictional - exerted as an object moves across or tries to move across a surface; two types are sliding (moving) and static (at rest); usually opposes motion of object
 * tension - transmitted through string, rope, cable, or wire when pulled tight by forces on opposite ends which is pulled equally; goes along string
 * normal - support force exerted on object but other object in contact; can sometimes be horizontal
 * air resistance - special type of frictional force that acts on objects while in air; also opposes motion; usually negligible except for high speeds or large surface area objects
 * applied - force applied to an object by another object or person
 * spring - compressed or stretched on an object
 * action-at-a-distance forces - objects not actually in contact but can still exert push or pull
 * gravitational - massively large object attracts another toward itself like earth and moon; therefore equal to weight
 * Fgrav= m*g
 * electrical and magnetic are also examples
 * 1) What is the difference between mass and weight?
 * 2) weight - force of gravity on an object; related to pull of Earth; dependent upon the value of gravity on certain planet and distance from that planet
 * 3) mass - amount of matter contained by object; never altered by location, gravity, etc
 * 4) What is a free-body diagram and how do you draw one?
 * size of arrow reflects magnitude of force
 * direction is the direction of the force
 * must label and include all forces acted upon object
 * can help determine if force is balanced or unbalanced
 * 1) How do you determine net force?
 * it is the vector sum of all forces that act upon an object
 * vectors of equal magnitude and opposite direction will cancel each other out
 * net force causes an acceleration, so if acceleration then net force

=Lesson 3 - Newton's Second Law of Motion=
 * 1) What is Newton's second law?
 * explains if forces are unbalanced
 * acceleration of an object is dependent upon the net force acting on the object and the mass of the object
 * acceleration and net force are directly related
 * acceleration and mass are inversely related
 * acceleration in same direction as net force
 * F(net)=m*a
 * 1) What is the big misconception?
 * a force is not needed to keep an object in motion
 * unbalanced force is what causes acceleration

=Lesson 3 - Vectors=
 * 1) How do you add vectors?
 * head-to-tail is one method of vector addition
 * addition of vectors gives you the net force on the object
 * net force is zero when at equilibrium
 * forces are not balanced and there is a net force if object is acceleration
 * 1) What is resolution of forces?
 * single force resolved in two components
 * one (vertical) is directed up
 * other (horizontal) is directed right
 * component = influence of force in given direction
 * trigonometry is used to determine components
 * 1) What is equilibrium and statics?
 * equilibrium - state object is in when all forces acting upon an object are balanced
 * though not necessarily equal forces, just balanced
 * net force is zero and acceleration is zero
 * can be at rest and staying at rest
 * can be in motion but continues in motion at same speed and direction
 * static equilibrium - object is in state of equilibrium and at rest
 * 1) Let's revisit net force problems
 * angled forces are broken into two components: vertical and horizontal
 * these are used in place of the angled applied force
 * 1) What are inclined planes?
 * object on inclined surface will often slide down incline
 * rate of sliding down depends on steepness of incline
 * greater incline = greater rate
 * inclined plane is the inclined/titled surface
 * unbalanced force is what causes object to slide down
 * normal force is perpendicular to surface and weight (gravity) is directly downward so need to break into components to solve
 * 1) How do you solve two body problems?
 * solve for acceleration of objects and force between the objects
 * two different strategies for solving
 * determine acceleration and combine with analysis of individual objects to determine force transmitted between the different objects
 * individual object analysis to create a two-system equation to solve for the two unknowns