Is F=ma the only way to define force?

[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 occurred 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?

 

[PeterO]

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 occurred 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?

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

 

[Andrew Mason]

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 occurred 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?

This has been discussed at length in several threads eg: https://www.physicsforums.com/showthread.php?t=631147.

The concept of force exists independently of the second law eg. a standard spring exerts a standard force if stretched a standard distance. Double the number of such stretched springs and you double the force.

AM