Equations · Physics
Newton's second law
The net force on a body equals its mass times its acceleration.
F = ma
Aethel says
F equals m a
What it says
A force changes how an object moves, and the same force accelerates a light object more than a heavy one. Force and acceleration point the same way.
This form holds when the mass is constant; in general the force equals the rate of change of momentum.
Symbol by symbol
| Symbol | Say it | Means |
|---|---|---|
| F | F | the net force, in newtons |
| m | m | the mass, in kilograms |
| a | a | the acceleration, in metres per second squared |
Where you meet it
Every mechanics course.
Questions
How do you say Newton's second law out loud?
F = ma is read: “F equals m a.” That is exactly what Aethel says when it meets the formula in a book.
What does F mean in Newton's second law?
F (said “F”) is the net force, in newtons.
What does m mean in Newton's second law?
m (said “m”) is the mass, in kilograms.
Can I listen to the equations in my own textbook like this?
Yes. Upload a PDF, EPUB or text file and Aethel reads it aloud with every equation spoken as maths, the way it reads this one, and highlights each sentence as it goes. You can start free.