Originally Posted By: paul
each 100 kg mass has a force that it can apply to an object of
f=ma
-80N=100 kg x -.8 m/s/s

That -80N is the force applied by the accelerator to cause the -0.8m/s^2 acceleration.


Quote:

so the only force that can push against the pipe in the (-)
direction is the force that is the product of the 100 kg mass
times its acceleration.
which is -80N

correct?

No, that's the force pushing against the mass while it's accelerating.




Quote:
[accelerated towards the center of the turn as it passes through the turn , this acceleration is called angular acceleration.

The direction from the mass to the center obviously changes depending on the position of the mass in the turn, so the direction of the acceleration changes, so the acceleration isn't constant.

In half-circle turn, the acceleration can't be constant for that reason, but we can always make the "turn" using some mechanism that applies a constant force and causes a constant acceleration.



Quote:

since the 100 kg mass does not loose any of its velocity as it travels

Its velocity changes at it travels through the turn. Its speed does not. The change in velocity means it must transfer momentum with the pipe.