1. Chapter 3 Newton’s Inertia (Friction Included)

2. Friction µ is the greek letter “mu” and is the commonly used symbol/variable that represents friction. µ But what is Friction and why does it occur? Discuss....

3. Friction Friction is the force that acts between materials as they move past each other. Friction is created from the irregularities and differences in materials. Even very smooth surfaces have some microscopic ridges/grooves. These, clash with the opposite surface, and produce opposing forces.

4. The Perspective https://www.youtube.com/watch?t=70&v=Iq2 BII29oKM https://www.youtube.com/watch?t=70&v=Iq2 BII29oKM Friction often times works to slow down objects, as without it objects that interact at parallel angles would not affect each other. Friction Produces Heat.

5. F=ma In the same light that weight works as a function of Gravity.( W=mgh) Friction is included in Acceleration when trying to obtain the force of a system or object. When conditions are ideal, we ignore friction. In general we only ignore friction when learning elementary physics. Friction is very important!

6. F_frict= µ X F_normµ http://www.physicsclassroom.com/class/newt laws/Lesson-3/Finding-Acceleration http://www.physicsclassroom.com/class/newt laws/Lesson-3/Finding-Acceleration Please Practice these problems. Show Friction vs Applied force in Jenga.

7. Inertia and Newton A ball rolls down and endless/frictionless surface. It rolls until the end of time. An object that is not affected by any outside forces will keep on keeping on, this is based on an innate property of matter called inertia. By your book: Inertia is the property of a body to resist change to its state of motion.

8. Newton’s First Also called Law of Inertia; Objects at rest will stay at rest. Objects at uniform speed will remain at uniform motion. Unless these objects are affected by a non-zero net force. Simply Put, objects continue to move by themselves unless stopped. Only an initial applied force is necessary to accelerate the object, but not to maintain motion.

9. Mass- Measure of Inertia The More mass, the more Inertia. Thus, the heavier an object the more inertia it has and the greater the force it takes to slow that object down. Mass and Inertia have a directly proportional relationship.

10. Mass vs Weight Mass and Weight are not the same thing... Once again; mass is the amount of matter an object is composed of. Weight is the effect gravity has on an objects mass. If the Moon is said to have 1/5 th the gravity of Earth, than what would be the weight of a 500lb object on the surface of the moon? Would the objects mass stay the same or would it change like the weight did?

11. Answer A 500 lbs object on earth would weigh 100 lbs on the moon. The mass of the object would not change, as the object still has the same amount of matter within it. If we however were to change the amount of mass inside the object by adding matter to it, than the weight of the object would increase.

12. Mass in Kilograms Mass is measured in Kilograms. An object that has a 1 kg mass is also said to have about 10 Newtons of Force or 2.25 lbs of weight.

13. Mass, Volume and Density Density allows us to analyze why a pillow is much larger than a red brick, yet weighs much less. Density is how much matter is distributed over the amount of space an object covers. The formula D= m/v ; explains the relationship. A pillow has mass(matter) spread out over a larger volume. It also has less matter than the brick. A brick has more mass compacted into a small volume, thus feeling heavier than the pillow... Can you think of some more examples?

14. Some Equations So far we know F= force (N), F= ma, where m is mass and a is acceleration. µ is friction and F_friction= µ X F_n µ Weight = MgH or just Mg Density= Mass/Volume F_net= F1+F2+F3......