Thursday, 12 June 2014 12:50

## C6-17: FRICTION VS. PULLING ANGLE

• ID Code: C6-17
• Purpose: Demonstrate how pulling angle affects the frictional force
• Description:

A wooden board of weight w, lying on a sandpaper surface, is pulled at an angle a by a string connected to a spring scale. The force F required to move the board is given by: F = w / [ (1/u)cosa + sina]. Differentiating F with respect to a, the minimum force is seen to occur at the angle of repose, u=tana. Pulling horizontally is definitely not the most efficient angle!

Pull horizontally to determine u, then check the angle of repose by tilting the sandpaper surface. Then pull at a variety of angles to demonstrate that pulling at the angle of repose requires the least force.

• Availability: Available
• Loc codes: C6, ME1
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• #### C6-03: INCLINED PLANE - FRICTION WITH THREE BLOCKS

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• #### C6-04: FRICTION DIRECTION ON INCLINED PLANE

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• #### C6-12: SKIDDING AUTOMOBILE

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Show that the friction force depends linearly on the normal component of the applied force. Read More
• #### C6-17: FRICTION VS. PULLING ANGLE

Demonstrate how pulling angle affects the frictional force Read More
• #### C6-21: SUSPENDED ROD ON WATER

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