Mechanics:
Fan Cart with Sail

PIRA Class: 1H20.20

Purpose:
To demonstrate equal and opposite forces exerted on a fan and sail.

Description:
A sail is added to the dynamics cart with fan attachment causing the cart to remain still when the fan is run.

PEDAGOGY: First use a cart without the sail or turn the fan around so that it blows away from the sail allowing the cart to accelerate. Ask students to draw a FBD and/or explain why the cart accelerates (many will say the fan pushes the cart). Then turn the fan to face the sail showing that it no longer accelerates. After discussion, ask students to explain the problem with the "self-propelled magnet truck."

Equipment:
Dynamics cart, track, fan and sail attachments (the wooden part of the sail screws into the L shaped dynamics cart adapter piece)

Location:
Shelf 112 (sail is in bin with fan attachments), 145 (track)