College Physics I Physics 1401 Sixth Class

1
College Physics I - Physics 1401Sixth Class

• Motion and Force Ideas from Lab
• Free Body Diagrams
• Introduction
• Examples
• Activities
• Newtons First Law of Motion
• At rest
• Uniform Motion
• Lab Activity - Introduction to Force Lab

2
Motion Ideas from Lab

• What Causes Motion (or change in motion)?
• Forces
• Or, more precisely
• The Net Force

3
Motion Ideas from LabThe Incline Plane

• What Forces are acting on a cart moving on an
  incline?

4
Free Body Diagrams Diagrams

• Introduction and Purpose
• Why Free Body Diagrams are Useful?
• Diagrammatic Representation of Forces
• Links to Newtons Second Law of Motion or First
  Law of Motion
• Procedure - Drawing Free Body Diagrams
• Identifying the OBJECT
• Sketch and Isolating the Object
• Identifying Short Range Forces - where the
  object touches the environment
• Identifying Long Range Forces
• Drawing the Force Vectors - both magnitude and
  direction
• Coordinate System

5
Free Body Diagrams

• Handout
• At Rest
• Falling Freely
• On an Incline
• Moving at Constant Speed
• Moving with Acceleration
• Activity

6
Newtons First Law of MotionLaw of Inertia

• Net Force 0
• Unchanging Motion (a 0)
• At Rest (v 0)
• Book on Table
• Block on Incline
• Uniform Linear Motion (v is constant, but not 0)
• Dueling fan carts
• Car moving down highway

7
Newtons Second Law of MotionLaw of Changing
Motion

• Net Force ? 0
• Motion has to change (a ? 0)
• Object has to speed up, slow down and/or change
  direction
• OCS Study Guide
• Examples 1.13 - 1.16
• Conclusions
• More Examples
• ALPS Kit Examples

8
Next Class

• Homework to be Turned In
• Do Force Diagram Homework
• Finish Changing Motion Lab