Ch4_bonnettd

=toc= Chapter 4 - Newton's Laws =Notes = 11/14/11 =__Lesson 1:__ =  __Newton's First Law of Motion__ (Method #4) (A-D)

__Newton's First Law:__ What is Newton's First Law of Motion? - This law is sometimes referred to the law of inertia, and it states 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. - it will only change if something forces it to (the lazy law = need someone to force you to do something) - once you get started, you keep on doing what you're doing - __motion__ = constant motion, no change in motion unless and unbalanced force acts on the object...otherwise it will move at constant speed in a straight line

__Inertia and Mass: __ What is inertia? - Inertia is the resistance an object has to a change in its state of motion. How was Galileo related to inertia? - He reasoned that moving objects eventually stop because of a moving force called friction. In experiments using a pair of inclined planes facing each other, Galileo observed that a ball would roll down one plane and up the opposite plane to approximately the same height. What is mass? - Mass is the quantity that is solely dependent on the inertia of an object. A more massive object has a great tendency to resist change in its state of motion.

__State of Motion:__ What does "state of motion" really mean? -The state of motion of an object is defined by its velocity, the speed with a direction. - This means that inertia could be redefined as: tendency of an object to resist changes in its velocity.

__Balanced and Unbalanced Forces: __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">When is an object at equilibrium? - When all the forces acting upon an object balance each other, the object will be at equilibrium, which means that it will not accelerate. <span style="font-family: 'Arial Black',Gadget,sans-serif;">What is an unbalanced force? - A force that causes changes in the state of motion, meaning it causes acceleration. <span style="font-family: 'Arial Black',Gadget,sans-serif;">How do balanced and unbalanced forces relate to Newton's First Law? - If all forces act upon each other then they remain in equilibrium and the object will not change its original state. If they are unbalanced then the object will change its state. _ =<span style="font-family: 'Arial Black',Gadget,sans-serif;">__Lesson 2:__ = <span style="font-family: 'Arial Black',Gadget,sans-serif;"> __Force And It's Representation (Method #4) (A-D)__ <span style="font-family: 'Arial Black',Gadget,sans-serif;"> __<span style="font-family: 'Arial Black',Gadget,sans-serif;">The Meaning of Force __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">What is the meaning of force? - A force is a push or pull upon an object resulting from the object's interaction with another object. - There are two categories of forces: 1) Contact Forces 2) Action at a distance forces

__<span style="font-family: 'Arial Black',Gadget,sans-serif;">Types of Forces __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">What are the different types of forces? 1) Contact Forces: - Frictional = sliding and static friction are the two types, normally oppose the motion of an object - Tension = a pull force on the object - Normal = the support force that occurs between an object in contact with another stable object. - Air Resistance= opposes the motion of an object as it travels through the air - Applied = force applied by another person or object - Spring = compressed or stretched force attached to an object. 2) At a distance force: - Gravitational: when a large mass attracts other objects towards itself <span style="font-family: 'Arial Black',Gadget,sans-serif;">What is the difference between mass and weight? - Weight is the gravitational pull on an object that is based on mass (measured in N) - Mass is the actual make up of an object (measured in kg)

__<span style="font-family: 'Arial Black',Gadget,sans-serif;">Drawing Free-Body Diagrams __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">What is a Free Body Diagram? - A free body diagram is used to determine unbalanced and balanced forces. They show the relative magnitude and direction of different forces acting upon a system.

__<span style="font-family: 'Arial Black',Gadget,sans-serif;">Determining the Net Force __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">How can you determine the net force? - You can just add all of the forces together that are acting upon the object because it is the vector sum of the object.

= = =<span style="font-family: 'Arial Black',Gadget,sans-serif;">__Lesson 3:__ = <span style="font-family: 'Arial Black',Gadget,sans-serif;">__Newton's Second Law of Motion (Method #4) (A-B)__ <span style="font-family: 'Arial Black',Gadget,sans-serif;"> __<span style="font-family: 'Arial Black',Gadget,sans-serif;">Newton's Second Law __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">What is Newton's Second Law? - This law states that the acceleration of an object has two components: <span style="font-family: Arial,Helvetica,sans-serif;">1) The mass of the object <span style="font-family: Arial,Helvetica,sans-serif;">2) The net force of the obje ct __<span style="font-family: 'Arial Black',Gadget,sans-serif;">The Big Misconception __ <span style="font-family: 'Arial Black',Gadget,sans-serif;">How does the Big Misconception relate to Newton's Second Law? - It is the idea that sustaining motion requires a continued force - This isn't true according to Newton's second law. **__Addition of Forces:__** - Tail to Tail (most of the time) __**Resolution of Forces:**__ - These are forces that make up the parts of the vector. __**Equilibrium and Statics:**__ - When all the forces that act upon an object are balanced, it is in a state of equilibrium. - You can use trig functions and break them up into components. __**Net Force Problems:**__ - Two components are a replacement for the single force. - The Net Force can be determined by adding all of the forces as vectors and the acceleration can be determined as a ratio of Fnet/mass. __**Inclined Planes:**__ - Depending on how steep an inclined plane is, determines the rate at which an object slides down it **__Two Body Problems:__** - These problems are different because the objects are moving in different directions. - Still accelerating at the same rate though.
 * What should you keep in mind when drawing the soon-to-be added vectors?**
 * -** In order to determine the sign, you must see which way the vector is pointing.
 * What are components?**
 * How do you solve for these vectors?**
 * -** SOH-CAH-TOA
 * What does equilibrium mean?**
 * How can you find the resultant when you have a angle?**

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