Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Why p for Momentum?
Name: Laurie B.
Status: other
Age: 40s
Location: N/A
Country: N/A
Date: 11/24/2003


Question:
In Newton's law p=mv we understand that momentum = mass times velocity. What is the actual word p stands for? (Besides momentum we need the actual scientific word.) Can anyone help?


Replies:
I would be surprised if the answer were anything but the obvious, that the letter m was taken by "mass", so go choose another letter, that is not being "used".

Steve Ross


I am afraid I cannot help in that, after teaching university level physics, mainly to undergraduates, for some 45 years, I do not believe I have ever heard that p stands for any other word than momentum in this context. I cannot imagine using another letter for momentum, but that is probably due to my long association with p.

I suppose p was chosen (probably not from the beginning), since it was not used for any other commonly used quantity. For example, you would certainly not use t, m, a, v, c, or F, since they are commonly associated with other quantities. It is amusing that they all (except for c) are the first letter of the quantity they commonly represent. I suppose that if mass had not gotten there first, we would be using m for momentum.

Best, Dick Plano...



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory