One is a static force (tracking force)
The other is dynamic (effective mass).
Static force is unaffected by mass.
Any wriggles of the stylus also produce a force. In this case the equation of F=MA comes into play.
Imagine shaking a blowing ball with a point of force… (as you shoulders are shaking 180 degrees out of phase.)
If you do the same with a feather, that same one pound of force would throw it across town if it were not for wind resistance.
Or do you thing of 1 pound as a mass? Rather than as a force?
Do you think of a kg as a mass, or as a force of ~10 newtons?
Imagine putting big 40” tyres on the 911.
Every bump in the road will have the tyres and wheel trying to propel the chassis.
Now load down the 911 with a tonne of Tesla batteries, and it will ride smoother.
Analogies:
- The tyres are the cartridge
- The chassis the effective mass
- The road the LP’s groove