Phys 103 - BlackBoard Notes: Radial Force

Radial Force
BlackBoard Notes

======================= Photo - Click for a Larger Version =============================

Need new photo Fall 2026: Use T instead of <T>

======================= First Board Section =============================

Measure the force exerted on Bob by a spring…

…when Bob is rotating
…when Bob is at rest

Check the notation used for the class: Are they FBDs (Free Body Diagrams) or Force Diagrams?
- What are the FBDs Bob (rotating and at rest)?
If unsure, write the following (which I usually do)
- {FBD ≡ Free Body Diagram ⇒ Force Diagram}

======================= Second Board Section =============================

Rotating Bob:

Measure d with ½-m stick & calipers (record both caliper positions)
Measure D_shaft & D_pointer with vernier calipers
What is the force diagram for Bob while rotating? Draw on graph paper

======================= Third Board Section =============================

Calculations: Assume a circular orbit:

Bob's orbit

.

Velocity Acceleration

{(Point to each parameter) ω ≡ "omega", f ≡ frequency, T ≡period, m = Bob's mass}

So: F_{Spring (Rotate)} = ma_radial

======================= Fourth Board Section =============================

Bob at rest:

What is the force diagram for Bob when at rest?
What is the force diagram for m₂ when at rest?
- Show how this allows you to calculate F_{Spring (Rest)}

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