I don't normally watch many NASCAR races, but I do come across some NASCAR videos online. Sometimes these clips become the basis of a great physics problem. In this case, it's a 21-car crash at the ...

It's perhaps the second week of your introductory physics course. Your instructor starts talking about friction and writes the following two formulas on the board. Then there is probably some sort of ...

This acts when an object is at rest and prevents it from starting to move. It increases up to a certain limit as you apply an external force to initiate motion. This acts when an object is already in ...

1.1 What is friction? Take this everyday example: when a coffee mug rests on a flat table, the kinetic frictional force is zero. There is no force trying to move the mug across the table, so there is ...

A new equation for accurate approximation of the Moody friction factor in the general gas-flow equation better approximates a wide range of Reynolds numbers than previously published equations. Other, ...

Friction is an intrinsic physical phenomenon to curling. Without it, objects in motion would move endlessly, without slowing down. This would cause many safety-related problems: Cars or trains could ...

The friction-fighting properties of synthetic lubricants have been well established by now. Second only to making sure you change your oil at regular intervals is the need for a high-quality synthetic ...