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-Two things friction depends on?
The type of surfaces and the amount of force used to push the objects together
-Kinetic vs. Static
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Static friction
surface. The coefficient of static friction, typically denoted as μs, is usually higher than the coefficient of kinetic friction.
The static friction kinetic friction.
The maximum value of static friction, when motion is impending, is sometimes referred to as limiting friction,[11] although this term is not used universally.[4]
Kinetic_friction (Wikipedia)
Kinetic friction
Kinetic (or dynamic) friction occurs same materials.
Examples of kinetic friction:
Kinetic Kinetic friction is kinetic friction.
Fluid friction is the interaction between Or a solid object and a fluid (liquid or gas), as the object moves through the fluid. The skin frictionbook sliding off of air on an airplane or of water on a swimmer are two examples of fluid friction. This kind of frictiondesk is not only due to rubbing, which generates a force tangent to the surfaceanother example of the object (such as sliding friction). It is also due to forces that are orthogonal to the surface of the object. These orthogonal forces significantly (and mainly, if relative velocity is high enough) contribute to fluidkinetic friction. Fluid friction is the classic name of this force. This name is no longer used in modern fluid dynamics. Since rubbing is not its only cause, in modern fluid dynamics the same force is typically referred to as drag or fluid resistance, while the force component due to rubbing is called skin friction. Notice that a fluid can in some cases exert, together with drag, a force orthogonal to the direction of the relative motion of the object (lift). The net force exerted by a fluid (drag + lift) is called fluidodynamic force (aerodynamic if the fluid is a gas, or hydrodynamic if the fluid is a liquid
(Wikipedia)

A force opposing motion. As soon as there is movement there is friction.
-Coefficient of Friction
of friction.
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-Two things friction depends on?
-Kinetic vs. Static
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Static friction
Static friction is friction between two solid objects that are not moving relative to each other. For example, static friction can prevent an object from sliding down a sloped surface. The coefficient of static friction, typically denoted as μs, is usually higher than the coefficient of kinetic friction.
The static friction force must be overcome by an applied force before an object can move. The maximum possible friction force between two surfaces before sliding begins is the product of the coefficient of static friction and the normal force: f = μsFn. When there is no sliding occurring, the friction force can have any value from zero up to Fmax. Any force smaller than Fmax attempting to slide one surface over the other is opposed by a frictional force of equal magnitude and opposite direction. Any force larger than Fmax overcomes the force of static friction and causes sliding to occur. The instant sliding occurs, static friction is no longer applicable and kinetic friction becomes applicable.
An example of static friction is the force that prevents a car wheel from slipping as it rolls on the ground. Even though the wheel is in motion, the patch of the tire in contact with the ground is stationary relative to the ground, so it is static rather than kinetic friction.
The maximum value of static friction, when motion is impending, is sometimes referred to as limiting friction,[11] although this term is not used universally.[4]
Kinetic_friction
Kinetic friction
Kinetic (or dynamic) friction occurs when two objects are moving relative to each other and rub together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as μk, and is usually less than the coefficient of static friction for the same materials.
Examples of kinetic friction:
Kinetic friction is when two objects are rubbing against each other. Putting a book flat on a desk and moving it around is an example of kinetic friction.
Fluid friction is the interaction between a solid object and a fluid (liquid or gas), as the object moves through the fluid. The skin friction of air on an airplane or of water on a swimmer are two examples of fluid friction. This kind of friction is not only due to rubbing, which generates a force tangent to the surface of the object (such as sliding friction). It is also due to forces that are orthogonal to the surface of the object. These orthogonal forces significantly (and mainly, if relative velocity is high enough) contribute to fluid friction. Fluid friction is the classic name of this force. This name is no longer used in modern fluid dynamics. Since rubbing is not its only cause, in modern fluid dynamics the same force is typically referred to as drag or fluid resistance, while the force component due to rubbing is called skin friction. Notice that a fluid can in some cases exert, together with drag, a force orthogonal to the direction of the relative motion of the object (lift). The net force exerted by a fluid (drag + lift) is called fluidodynamic force (aerodynamic if the fluid is a gas, or hydrodynamic if the fluid is a liquid

A force opposing motion. As soon as there is movement there is friction.
-Coefficient of Friction
The ratio of friction between two objects and the forces pushing them together. The coefficient of friction depends on the materials used; for example, ice on steel has a low coefficient of friction, while rubber on pavement has a high coefficient of friction.
-Two things friction depends on?
-Kinetic vs. Static

-Friction:
A force opposing motion. As soon as there is movement there is friction.
-coefficient-Coefficient of fiction
-twoFriction
-Two things friction depends on?
-kinetic
-Kinetic vs. staticStatic

2. (not moving) When you press the gas petal in your car you notice that the coffee in your mug begins to move in the opposite direction of the way you are traveling.
2nd Law
-net-Net force (2
-the sum of forces acting on an object
- Resultant Vector :a single force whose external effects on a rigid body are the same as the effects of several actual forces acting on the body.
(ex. You see a book sitting on a table. Normal force is the gravitational force exerted on the book by the table.)
-Action reaction pairs
ForcesIn every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs.
-Friction:
A force opposing motion. As soon as there is movement there is friction.

1st law:
An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
{http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/newtlaws/u2l1a1.gif} external image
-Inertia:image-Inertia:
The tendency of an object to resist being moved, or if the object is moving, to resist change in speed and direction.
-Two examples from life:
-net force (2 definitions)
-the sum of forces acting on an object
-a- Resultant Vector :a single force the body.
-force diagram example (pg.126)
-differences
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-Differences between weight vs. mass (example with moon)
The mass of an object refers to the amount of matter that is contained by the object; while the weight of an object is the force of gravity acting upon that object. Weight is related to the pull of the earth on an object while mass is related to the density of an object. The mass of an object never changes, while weight can vary depending on where in the universe the object is located.
Ex. If an object with a mass of 3kg on earth was taken up to the moon it would still contain a mass of 3kg but it would weight less because gravity is not as strong on the moon.
- If two objects interact, the magnitude of the force exerted on object 1 by oject 2 is equal to the magnitude of the force simultaneously exerted on object 2 by object 1, and these two forces are opposite in direction.
(For every action, there is an equal and opposite reaction)
-normal force:-Normal Force: Fnorm
The normal force is the support force exerted upon an object which is in contact with another stable object.
(ex. You see a book sitting on a table. Normal force is the gravitational force exerted on the book by the table.)
-action-Action reaction pairs
Forces come in pairs
-Friction-Friction:
A force opposing motion. As soon as there is movement there is friction.
-coefficient of fiction
-two things friction depends on?

- If two objects interact, the magnitude of the force exerted on object 1 by oject 2 is equal to the magnitude of the force simultaneously exerted on object 2 by object 1, and these two forces are opposite in direction.
(For every action, there is an equal and opposite reaction)
-normal force:
The normal force is the support force exerted upon an object which is in contact with another stable object.
(ex. You see a book sitting on a table. Normal force is the gravitational force exerted on the book by the table.)
-action reaction pairs
Forces come in pairs