- #36
user079622
- 299
- 20
action force is centripetal?kuruman said:here is an "action" force on the mass but the mass can exert no "reaction" force on anything because it doesn't exist. .
What you say about my post #34?
action force is centripetal?kuruman said:here is an "action" force on the mass but the mass can exert no "reaction" force on anything because it doesn't exist. .
I say that's a different physical situation. I am considering a simpler case to answer your questionuser079622 said:action force is centripetal?
What you say about my post #34?
and I have answered that.user079622 said:why we need introduce fictive forces if object dont accelerate?
You would still be double dipping. The two sources are still not independent.user079622 said:But if moon rotate very fast,(so no synchronous rotation) we have now two sources of centripetal acceleration, revolution and rotation?
Why not then?
jbriggs444 said:You would still be double dipping. The two sources are still not independent.
What do mean by "has same centripetal force"? Maybe draw a diagram and label is properly.user079622 said:So you want to say that ball that revolving 500rpm and spinning 1000rpm has same centripetal force as ball that is only spinning 1000rpm?
This sound impossible.
I mean centripetal acceleration,A.T. said:What do mean by "has same centripetal force"? Maybe draw a diagram and label is properly.
Be careful. Are you specifying a "sidereal" rotation rate? Or a rotation rate relative to a frame that rotates with the orbit?user079622 said:So you want to say that ball that revolving 500rpm and spinning 1000rpm has same centripetal acceleration as ball that is only spinning 1000rpm?
This sound impossible.
Tangential velocity and radius of point A and B are different.jbriggs444 said:The bug is moving with the ball. And we've already accounted for the acceleration associated with that spin.
What is providing the centripetal acceleration? Gravity or a carousel?user079622 said:So you want to say that ball that revolving 500rpm and spinning 1000rpm has same centripetal acceleration as ball that is only spinning 1000rpm?
This sound impossible.
jbriggs444 said:What is providing the centripetal acceleration? Gravity or a carousel?
carousel
But I didnt mention normal force for this task.jbriggs444 said:So not relevant to the normal force on the moon.
user079622 said:We learned that normal force equal in magnitude as mg and opposite direction, it is reaction force to gravity.
1.If normal force is not equal gravity, isnt this violate newton 3. law action=reaction?
2. If gravity is higher than normal force , this system has net Force non zero,it means accelerate in dircetion of higher force ,which is not true?
3.Professor say it must be higher otherwise we will not move with earth?
It can be equal, when rotate stone with rope,stone pull your arm with same force as arm pull stone,so not need to be higher..
The presenter made a very misleading statement.user079622 said:16:23