What are three examples when friction is useful?

Answer 1

Friction is useful in these situations (and more):

• sanding wood to prepare it for stain or varnish
• shaving rough spots off of metal
• scrubbing out a ring of dirt around the inside of a bathtub
• drying off after a bath
• removing dead skin from your body
• lifting dirt from deep inside a carpet
• scrubbing a counter top or floor
• scrubbing pots & pans with an SOS pad (steel wool)
• cleaning the ends of pipes before affixing them together
• cleaning the inside of a gun
• cleaning the inside of a chimney used for a fireplace

Answer 2

1. The friction between your shoe soles and the ground helps prevent slipping and falling.
2. Friction between the brake pads and wheels of a car allows the driver to slow down or stop the vehicle.
3. Friction between the strings and fingers of a guitar player is essential for producing sound while playing.