St. Andrew’s Advanced Physics

Pumpkins and Force Diagrams

Written Description

Interaction Diagram (ID)

Each interaction that crosses the dashed system boundary is one force on the free body diagram.

Sketch

Free Body Diagram (FBD)

Click a force to bring it to the vector addition diagram. Until then its arrow shows direction only; once it’s in the VAD, its length here matches the VAD.

    Force Vector Addition Diagram (VAD)

    VAD reference (PDF)

    Rearrange the vectors head-to-tail to add them. You can adjust the length until you think the result of the force vector addition is consistent with the motion of the pumpkin.

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