Recent content by Mad_Eye

someone?

okay thanks a lot.. a few questions though, i don't see how this calculation is true... the body SHOULD have torque which is not necessary zero... and i don't understand what's the meaning of ignoring the moment of inertia... anyway.. what if you are considering the moment of inertia

yes yes i know if you know where the forces are applied, what direction they have, and everything you need.. how can you determined the center of rotation?

say i have a lever, fixed to an axis in its right end. now a perpendicular force is exert on the lever, from its left end. the lever will obviously rotate relatively to the fixed axis. (the force will rotate with it, and will always be perpendicular to the lever. so the lever has a fixed...

THANK YOU that what i wanted to say.. no, that have nothing to do with physics that's true for almost any set of rules (may be every set of rules, i don't know i need to think about it) and yet, there fundamentals axioms that should be decided... for example you can say the shortest...

well, you might say it an axiom yes.. but however, regarding a body as a set of not spinning particles, each with independent velocity and acceleration, should let you solve it without angular mechanics... right?

sorry if the title is not clear, if you have a better idea i'll change it. say i drop a 10kg book to the floor. when it reach the floor, the floor stops it by "activating" the Normal force on it... my question is, how much time does it take to the floor to stop the book, and by this time...

as far as i know angular mechanics contains no axioms in it. it just a helpful tool to solve problems with a rotating body, but technically if you regard the body as a set of independent particles you should be able to solve any problem without angular momentum, right? so how can you show a...

but.. what? the net torque is not zero.. and what the different between a spinning gyro and a non spinning..?

:mad: damn, I actually thought about it, and some why deny it.. because seemingly in the first infinitesimal moment it still perpendicular. so what about gyroscope, that stand still in unnatural way...

A body is tied to a wire that go through a hole in a (frictionless) table on which the body is spinning. The body is spinning while the wire is pulled from beneath the table. according to conversation of angular momentum the speed of the body should now increase, but in terms of forces...

yes, i know i probably said rubbish regarding technical terms, that why i mentioned i have to learn thermodynamics, but this is an empiric fact :P i have a lot of metal stuff here, and they are all definitely colder than the room temperature..

sure it is possible! even without a fan... it's a metal piece. it's naturally getting cold, even more than the room temperature. now it's very improbable, cause the cpu is working, and is near to bla bla bla... but there are definitely materials that goes below rooms temperature by them self...

I haven't read all the comments yet, but as I sure you have been told, there is nothing to prov here, those are axioms, this is just the way our world is. And proving it with conversation of momentum is meaningless, because conversation of momentum, is proved by the third law, and if not, how...

but why do you think there must be a material to transfer a force, or field? a field is probably something that just can transfer forces, and exist in a vacuum - that what's fields are for. if perfect vacuum is a space with no material at all, what the problem of a field exist in it, which is...