# What is infinitesimal displacement? [duplicate]

This section is from the Openstax University Physics: Volume 1 online textbook.

In physics, work is done on an object when energy is transferred to the object. In other words, work is done when a force acts on something that undergoes a displacement from one position to another. Forces can vary as a function of position, and displacements can be along various paths between two points. We first define the increment of work $$\text dW$$ done by a force $$\mathbf F$$ acting through an infinitesimal displacement $$\text d\mathbf r$$ as the dot product of these two vectors:

Is it simply just a very small displacement?

## marked as duplicate by Aaron Stevens, Bob D, John Rennie, Jon Custer, Kyle KanosOct 23 at 11:41

• Is $10^{-9}$ meters close enough to zero displacement to be an infinitesimal displacement? No. And neither is any other finite displacement. You are ignoring more than 300 years of calculus. – G. Smith Oct 20 at 22:28