Recent content by mmeftahpour

If rubber tension is negligible it is isobaric otherwise we can consider P=f(V), and f depend on rubber specification and balloon dimensions. https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/59/59222-ef0af70f5c70ec1351bf0a5e6d506887.jpg I

I educated in mechanical engineering, but my favorite is physics and mathematics. I join this form to learn more about physics and discuss with others about this subject.

please see attachment.

Dear Dave Please look at pdf file(my first post in this page). if we release a ball from tower with 400 m height there is 17 cm eastward deflection.(free fall in rotating Earth - page 8)

I have a question. they make it in circle form, because there is no need for external energy. (just energy of river) if you want to use electrical motor why you use the wheel?

Sit relax and just move your feet forward and backward. what append? you and swing start to move backward and forward. why? consider you stand on boat. if you walk to left, boat goes to right.(system mass center is constant) In our swing system our feet and rest of the body with swing is a...

yes, for human speed that's true and it is very very small, but in general view, for example if you shoot gun vertically, and bullet goes up 10 km. it fall in the same point? (consider there is no wind.)

Car crash finish in 80 ms. in time 30 ms, head impact to steering. for explosion of airbag roughly we need 10~15 ms (for full filled) so we have something about 15 ms (golden time) to decide for firing or not. there is a ACU in car, with acceleration sensor in different direction(for detecting...

Dear Dave that's true for train, because the the train is Constant-Velocity, Non rotating Systems. but I think it is not applicable for a system on the Earth surface.(with variable velocity direction and also axis direction.

Dear friends, we have a discussion with thegodof3d. I say when you jump on the earth, we fall in different point because of Earth rotation. for small speed it is very small, but for larger amount it is considerable. I know we carry angular momentum when we jump, but our movement is not equal to...