Ch4_BehrensB

Chapter 4 - Newton's Laws toc

= Newton's Laws - Lesson 1; a, b, c, & d = November 14, 2011 Method 4: SQ3R

__ Questions: __ What is Newton's first law, and how does it apply to everyday life?
 * Newton's first law - law of inertia
 * An object will continue in its current state (such as rest or constant motion) unless acted upon by an unbalanced force
 * "Objects keep on doing what they're doing" (www.physicsclassroom.com).
 * Ex: coffee in a coffee cup while in an accelerating car; a breaking car & passengers within it

How do inertia and mass affect the motion of an object?
 * Inertia - an object's resistance to motional changes in velocity and acceleration
 * An object will continue in its state of motion unless an unbalanced force affects the inertia.

What did Galileo discover / state about the concept of inertia?
 * Concept of inertia - developed by Galileo (seventeenth century)
 * Motion of moving objects ceases due to force of friction

What continues an object's motion?
 * Forces are not needed in order to keep an object in motion
 * Motion stops in the presence of a force, not the absence of a force
 * Without the action of a force, motion would continue

How does mass relate the amount of inertia (of an object)?
 * Mass - depends on the inertia of an object
 * Inertia varies with mass
 * Objects of greater mass have a greater inertia

What is an object's state of motion?
 * State of motion - the object's velocity (direction and speed)
 * Zero velocity / at rest - does not change its state of motion (unless acted upon by an unbalanced force)

What are balanced an unbalanced forces? What is the relationship between these forces, and what effect do they have on an object, either in motion or at rest?
 * Balanced forces - forces in opposite directions and equal magnitudes, which enable an object to continue its state of motion
 * Unbalanced forces - forces that have no counter-part, and therefore cause changes in inertia / state of motion (ex: book sliding across a table = friction)
 * Balanced forces allow an object to maintain its current state of motion, while unbalanced forces change the motion of an object

= Newton's Laws - Lesson 2; a, b, c, & d = November 16, 2011 Method 4: SQ3R

__ Questions: __ What is the meaning of force?
 * force - a push or pull on an object as a result of contact with another object
 * contact forces - forces of physical contact
 * action-at-a-distance forces - forces with the ability to exert push or pull despite physical distance
 * balanced vs. unbalanced

What different types of forces exist?
 * applied force - a force that is applied by an object
 * gravity force / weight - a pull by a massive object (i.e. the earth) exerted on another object
 * normal force - a support force applied by one object on another
 * friction force - a force applied when two surfaces move across each other
 * air resistance force - a friction force for objects as they move through the air
 * tension force - a force applied by a rope, string, chain or wire
 * spring force - a force exerted by a compressed spring on the object attached to it

What is the difference between mass and weight?
 * mass - the amount of matter within an object
 * weight - the gravitational force exerted on an object

What are the most important factors in drawing a free body diagram?
 * free body diagrams - a type of vector diagram in which all of the forces acting upon the object are depicted
 * always separate the system from its surroundings
 * arrows in the direction of which the force is pointed

What is a net force, and how is it determined?
 * net force - vector sum of all forces acting on an object
 * add the forces in the process of adding vectors, with appropriate labels

= Newton's Laws - Lesson 3; a & b = November 17, 2011 Method 4: SQ3R

__ Questions: __ What are the main principles of Newton's second law of motion? What is a common misconception pertaining to Newton's second law? = =
 * depicts the behavior of objects for which all forces are not balanced
 * acceleration depends on net force (directly) and object mass (inversely)
 * net force - vector sum of all forces
 * F net = m • a
 * misconception - continued motion requires continued force
 * no force is needed to keep a horizontally-moving object in motion