Calculating Friction with Free-Body Diagrams
Learning Objective
I can draw a free-body diagram and use it to calculate the coefficient of friction.
Lesson Flow
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Guided Notes
Key concepts students will learn:
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Kinetic friction slows objects down as they slide, while static friction must be overcome to start an object's movement.
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The force of kinetic friction depends on the coefficient of kinetic friction (μₖ) and the normal force (F_N), and is calculated as F_friction = μₖ * F_N.
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When an object is on a ramp, the normal force is equal to (mg) x (the cosine of the angle), where mg is the weight of the object.
Practice
12 questions • Multiple choice & Short answer
Exit Ticket
“A 10 kg box is placed on a horizontal surface. A force of 49 N is required to start the box moving. Draw a free-body diagram of the box, labeling all forces. Then, calculate the coefficient of static friction (μₛ) between the box and the surface. Show your work.”
Teacher Guide
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