Forces and Inertia Monday, September 22, 2014

Monday, 9/22 Unit 3: Work and Forces  Note the upcoming dates in your planner.  Take out your forces article from Thursday. If you have not written your summary use your three minutes to do so.  If you were not here on Thursday pick up the forces notes (in the blue Physics bin).  Upcoming dates  Monday, 9/22 - last day to turn in 1SW extra credit  Friday, 9/26 – quiz (grade will go on 2SW)  Friday, 9/26 - end of the 1SW  Thursday, 10/2 – quiz  Wednesday, 10/8 – quiz  Friday, 10/10 – Unit 3 test

Revisiting Work  Take out your CNs on Power.  Form your own groups (no more than 4 to a group) and choose a leader.  On your group paper address the following:  Create a group name and write it on the top.  Write the members of the group on the back of the paper.  Use your work notes to summarize what work is (be sure to include the components of work).  Draw a picture of work being performed  Draw a picture in which work is not done

 Work is the exertion of a force that causes movement.  Work is only done by a force on an object if the force causes the object to move in the direction of the force.  Objects that are at rest may have many forces acting on them, but no work is done if there is no movement.  The two components required for work are a force and displacement.  The direction of the force applied and displacement need to be the same in order for work to be done. Work Notes Reviewed

Work examples/non examples

Work Practice  With your group members complete the work practice sheet.

Forces article  Take your force article to the back table and send your group leader to me.  Answer the following questions: 1. What is a force? 2. What is a balanced force? 3. What is an unbalanced force? 4. Compare and contrast balanced force and unbalanced.

Inertia  Video guide questions  How are mass and weight different?  How does mass affect inertia?  How would you describe inertia after watching the video?

Watch video /science-of-nfl-football

& ForcesForces

Isaac Newton Isaac Newton (1642–1727) Isaac Newton proposed that the tendency of an object was to maintain in its current state of motion.

“Law of Inertia” An object at rest remains at rest, and an object in motion continues in motion at a constant speed in a straight line, unless acted on by a nonzero net force (unbalanced force). * OR * The velocity of an object remains constant unless acted on by an unbalanced force. Newton’s First Law of Motion

Objects tend to stay at rest OR object tend to stay in motion at a constant speed.