Section 05: Forces

Goals: To show that Newton’s First Law of Motion is derived from Galileo’s Principle of Inertia and to identify everyday manifestations of the phenomenon of inertia; To demonstrate that a non-zero net force will always produce a change in velocity; To explain action/reaction forces and the evidence of their existence in everyday situations.

Objectives:

Students will be able to:

- describe the historical development of Newton’s understanding of motion.

- define inertia.

- state Newton’s first law of motion.

- distinguish among mass, volume, and weight.

- distinguish between the kilogram and the Newton as units of measurement.

- explain how something that is not connected to the ground is able to keep up with the moving earth.

- explain why a clothesline or wire that can easily support an object when strung vertically may break when strung horizontally while supporting the same object.

- for an object on a slope, resolve its weight into a component that causes acceleration along the slope and a component that presses it against the slope.

- define and explain net force.

- state the relation between acceleration and net force.

- state the relation between acceleration and mass.

- distinguish between the concepts of directly proportional and inversely proportional.

- state and explain Newton’s second law of motion.

- describe the effect of friction on a stationary and on a moving object.

- distinguish between force and pressure.

- apply Newton’s second law to explain why the acceleration of an object in free fall does not depend upon the mass of the object.

- describe what happens to the acceleration and the speed of a falling object when there is air resistance.

- define force in terms of interaction.

- explain why at least two objects are involved whenever a force acts.

- state Newton’s third law of motion.

- identify the reaction force if given an action force

- explain why the accelerations caused by an action force and by a reaction force do not have to be equal.

- explain why an action force is not canceled by the reaction force.

- develop, explain and use free body diagrams.

-calculate the net force acting on an object and use it to obtain and acceleration

-Use the net acceleration acting on an object and the kinematic equations to describe and calculate changes in an objects motion.

Labs:

1. Basic 1st & 2nd Laws of Motion Lab - Finding the acceleration of an object graphically and by using 2 different acceleration formulas.

2. Friction - calculate the coefficient of friction for a variety of surfaces.

3. Newton's 2nd law of Motion Part I - Its a surprise!

4. Newton's 2nd law of Motion Part II - Its an even better surprise!

5. Newton's 2nd law of Motion Part III - Awesome!!!!

6. Inclined planes and gravity.

7. Inclined planes and associated forces.

Worksheets: See below list.

For extra problem sets click download the files that contain "Test Yourself" in the title.

Reading Assignment: Chapters 2, sections 2.1-2.8, 4 and 5

Conceptual Development Worksheets("Concept Sheet" will be in the title)

Extra Credit: None at this time, but if you have any ideas, write up a proposal and I'll review it for consideration

Class Updates/Test/Quiz Schedule: Check your SOE for all test and quiz dates.