Explore how forces and friction work to hold a block against a vertical wall. This video explains normal force, frictional force, and equilibrium conditions, showing how these forces balance to ...

Ask anyone who has had to drag a heavy object over a large distance – the bigger and heavier the object is, the harder it is to drag. This is because friction increases with size and weight for a ...

In this video, we explain the capstan equation and how friction affects a rope or string wrapped around a surface. You’ll learn where the equation comes from, what each term means, and how it’s ...

Sometimes you think you have a complete understanding of something and then BOOM—a simple problem throws everything out the window. Let's consider a very basic physics problem involving pushing a ...

At a busy street crossing, people wait for the signal to change. When one person steps out first, others soon follow. Scientists in Amsterdam have found that this same kind of behavior happens at a ...

Is friction real? Once, with the quiet certainty of someone who just stayed up all night in the company of equations describing concrete, my college roommate told me that friction was made up. Now, ...

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 ...

Humans have been making fire using friction for thousands of years, with evidence of its use found in archaeological records across different cultures worldwide. Fire by friction is a testament to ...