# Why F=ma

1. Nov 11, 2012

### aaaa202

I thought to myself yesterday: Is there really any way of measuring a force independent of F=ma? I don't see there is so you can more or less take F=ma as the definition of force and then use that to derive the expressions for the fundamental forces of nature. But then it occured to me: Why did we then choose F=ma. Why didnøt we just pick F=mdx/dt and adjusted the expressions for the fundamental forces from that?

2. Nov 11, 2012

### PeterO

http://en.wikipedia.org/wiki/Torsion_bar_experiment

3. Nov 11, 2012