1. Review of Previous Lesson
12/9/2018
State as many Vocabulary words and Learning Objectives that you remember from the last lesson as you can.
Now complete the content learning objectives.
Remember to grade yourself from 0 – 3.

2. Free Body Diagrams (FBD)
12/9/2018
Free Body Diagrams (FBD)

3. Vocabulary Content: Start End 12/9/2018 force
Fg, Fn, Ft, Fa, Ff, Fp, Fair
free body
diagram

4. Vocabulary Language: Start End 12/9/2018 types define identify
distinguish
draw
centre/center
square/dot

5. Learning Objectives Content: Start End 12/9/2018
Define and identify contact and action at a distance forces.
Define, identify and distinguish between the following forces: Fg, Fn, Ft, Fa, Ff, Fp, Fair.
Draw free body diagrams from descriptions of situations.
Understand that centres of free body diagrams may be squares or dots.

6. Learning Objectives Language: Start End 12/9/2018
Define, identify and distinguish verbally and in writing.
Draw from written descriptions.

7. AP Physics College Board “FBD” Rules
12/9/2018
You will many different ways of drawing FBD’s on the internet and in books. However, these are the ways AP exams expect you to draw them.
There are actually some good reasons for their rules – see next slide.

8. AP Physics College Board “FBD” Rules
12/9/2018
No boxes, just a LARGE (~o.5 cm) clearly visible dot .
Reason: FBD’s are about forces so the shape is completely irrelevant and where the forces act on an object (e.g. top, bottom, etc..) is also irrelevant – also see below.
All force “arrows” must start from this dot, pointing away from the dot and the length represents the force size.
Reason: See above and the “length” issue is true for all FBD’s you will see.
No overlapping forces.
Reason: Forces do not act on each other, they act on the object.

9. Types of Forces
12/9/2018
/Lesson-2/Types-of-Forces

10. 12/9/2018
Free Body Diagram: (Physics Classroom)
Used to show the relative magnitude and direction of all forces acting upon an object in a given situation. 
The size of the arrow in a free-body diagram reflects the magnitude of the force.
The direction of the arrow shows the direction that the force is acting.
Each force arrow in the diagram is labelled to indicate the exact type of force.
It is generally customary in a free-body diagram to represent the object by a square box or dot and to draw the force arrow from the centre of the box or dot outward in the direction that the force is acting.
Objects do not necessarily always have four forces acting upon them.

11. Problems and Solutions:
12/9/2018
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