# Friction – 1K20.00

## Friction Blocks – Surface Materials – 1K20.10

• Measure static friction by noting the scale reading just before the block slides.
• Measure sliding friction by pulling the block at a constant speed.
• Change the surface materials and note the different frictions.

## Static vs. Sliding Friction – 1K20.30

• Pull on a block with a spring scale until just before the block moves.
• Note the reading on the spring scale.
• Pull the block slowly across the table.
• Compare the spring scale readings.

Location: Demo Room

## Inclined Plane – Friction – 1K20.35

• Set an empty box on the inclining plane
• Increase the angle until it slides.
• Add weights to the box and repeat the experiment.
• The weighted box begins to slide at the same angle.
• This shows that the coefficient of friction does not depend upon the mass of the object.

Location: Demo Room

## Friction and Cord Around a Cylinder – 1K20.71

• Suspend two different masses with a cord around a fixed cylinder so that the masses are in equilibrium
• Add a mass on one side and observe the cord sliding.
• Wrap the cord around the cylinder once and see that the cord does not slide.
• Repeat adding more masses and wrapping the cord around the cylinder multiple times.
• The result is exponential.

Location: Demo Room