Ch4_Knapelr

toc Homework
11/14/11

What **is Newton's first laws?** This is the law of interita which refers to motion. It is defined by an object at rest will stay at rest and an object in motion will stay in motion unless there is an unbalanced force.

If you are driving in a car and start at rest with coffee in your cup holder, the coffee would also be at rest. Once you start to accelerate the road provides an unbalanced force causing the coffee to spill over.
 * How can Newton's laws be applied to everyday life?**

He siad that moving objects have to eventually stop because of friction. He also that that difference in initial and final height of a moving object is due to friction. if friction were to be eliminated then an object would reach the same height.
 * What is Galileo's concept of intertia?**

it is the presences of forces that slows objects down.
 * Why don't forces keep objects moving?**

The tendency for an object to change its motion from moving to rest will vary depending on the objects mass. Mass is dependent on the inertia of an object.
 * Hoe is mass a measure of the amount of intertia?**

Inertia is the tendency of an object to change its state of motion, it is also the tendency of an object to resist changes in its velocity and also accelerations.
 * what is state of motion?**

If the two objects have equal magnitude (are pushing at each other with the same force) and in opposite directions than the force is balanced and the object won't change its state of motion. This is at equilibrium. If their is no force to balance out another than the force would be unbalanced therefore leading to a change in its state of motion.
 * What are balanced and unbalanced forces?**

Homework
11/16/11

A force is a push or a pull. When two objects are in contact (an interaction) their is always a force being acted upon.
 * What is the meaning of force?**

When two objects that are interacting are physically contacting each other. Friction forces, tensional forces, normal forces, air resistance forces, and applied forces.
 * What are constant forces?**

When two objects that are interacting are not physically contacting each other, but they are able to push or pull without physically contacting the other object. An example of this is the sun and the planets, the sun has a gravitational pull on all of the planets even though they are not touching.
 * What is Action-at-a distance forces?**


 * What are the different types of forces?**
 * 1) Applied force - A force that is applied to an object by a person or another object.
 * 2) Gravity force - Force by which the earth, moon, or other massively large object attracts another object toward itself.
 * 3) Normal force - it is the force exerted when an object is in contact with another stable object.
 * 4) Friction force - Is exerted when an object moves across or attempts to move across a surface.
 * 5) Air resistance force - It is a type of frictional force that acts upon objects as they travel through air.
 * 6) Tension force - Force that is transmitted through a string, rope, cable, or wire when it is pulled tight by forces acting from opposite ends.
 * 7) Spring force - Force exerted by a compressed or stretched spring upon any object that is attached to it

Weight - gravity acting upon an object Mass - the amount of matter that the object contains
 * What is the difference between mass and weight?**

size of the arrows reflect that magnitude force. The direction of the arrow shows the direction of the force. Each arrow is labeled with the type of force that it is.
 * How to draw a free body diagram?**

The net force is the vector sum of all the forces.
 * How to determine net force?**

Homework
11/17/11

When all the forces are not balanced. Acceleration of an object is dependent on two things the net force acting on the object and the mass of the object. Acceleration depends directly on the net force and inversely with the mass. The second law states "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." The equation is: **Fnet = m * a**
 * What is Newton's second law?**

When all forces are balanced there is no acceleration.
 * What is acceleration due to a force?**

People are able to recite them, but are not able to understand them. People think that sustaining motion requires a constant force.
 * What is the big misconception?**

Homework
12/07/11 One of the forces is at an angle. This force can be split up into two components which replace the single force. These components are then used to solve problems.
 * What are net force problems with angles?**