# Search results

1. ### Pascal's law and pistons

oh no no Jim....I didn't feel you get curt on grumpy at all !!!!! I thought you were really patient and helpful bud. I was just an average student...and probably average intelligence. I don't think i would have made it past engineering school. But now that I am approaching 50, I am...
2. ### Pascal's law and pistons

Thank you so much for your help Jim...really appreciate your time and expert input. I was suspecting that because it was sealed that there was something not correct. You explained my suspicion about the vacuum in the sealed cylinder. I understand now why you say the large piston will go higher...
3. ### Pascal's law and pistons

The pressure i assume is higher on the side of the large piston because the sealed cylinder level is now higher. Remember that this sealed piston top was at same water level before as that on small diameter piston. If the small diameter water level can push down and raise the large piston...
4. ### Pascal's law and pistons

ok sorry Jim, my last post I meant to say the column on the right on top of the large piston. If that one is sealed, then how can the small diameter piston move down? Wouldn't that move the column on the large piston up and then the hydrostatic pressure on the right side be much higher?
5. ### Pascal's law and pistons

Jim, you say that the large piston would rise now and the water level in the left (open piston) goes down now. But I am assuming there is no way the water column on the left (which is closed), could fall and create a vacuum, and also then, if the large piston rises, the water level in the...
6. ### Pascal's law and pistons

@Jim - thank you. I was more curious about # 3 because I was thinking that both columns were adding a hydrostatic pressure upward on the bottom of the large piston. I was then thinking that it wouldn't be just some small incremental force, but some magnitude large enough to first overcome the...
7. ### Pascal's law and pistons

I have some questions in regards to a diagram that has a twist to the regular set up that is usually used with demonstrating Pascal's law and pistons. In the diagram I have attached, if you added a column of water on top of the large piston which is sealed at the top from the atmosphere, there...
8. ### How to attach a picture or diagram?

oh ok...thank you. I was wondering how to delete the thread :) My apologies and thanks.
9. ### How to attach a picture or diagram?

ok --thank you so much all of you. Sorry for all errors
10. ### How to attach a picture or diagram?

one final shot
11. ### How to attach a picture or diagram?

@DiracPool and Micromass-- thanks guys :) Let me give it a whirl g
12. ### How to attach a picture or diagram?

Can someone tell me what is the best way to attach a picture or diagram on my posts? Something that shows on my post without the reader having to open an attachment??
13. ### Measuring energy capture of river turbine

I know my questions are strange. To be honest Russ, i have a patent that I am trying to market which has relevance for my strange questions. And no, it's not some kind of perpetual motion wheel in the water...most people think that right away. I appreciate your help as always Russ.
14. ### Measuring energy capture of river turbine

eah, i know river don't flow that fast. I was just using examples for calculations. Was just thinking about the Verdant power company putting in all those small turbines in the Hudson River to catch tidal flow. Curious about their economics cause i heard it was so tough to put in the turbines at...
15. ### Measuring energy capture of river turbine

So 50,000,000 Joules give or take. That seems more right than 50. So if it was a really long river, it would be viable to put as many of these in as possible? I guess the last one may theoretically receive less because the water may be slowed down by the previous ones? I wonder why they...
16. ### Measuring energy capture of river turbine

50km/h = 0.014km/s E=0.5 *510,000kg * 0.014km/s *0.014km/s =49.98 Joules?? Does that look right?
17. ### Measuring energy capture of river turbine

hmmm...so w=f*d f=510,000kg*9.81m/s = 5,000,000 N w=5,000,000 *50km = =250,000,000 J So in one hour the turbine will capture the entire 510,000Kg of water moving at 50km/h for an equivalent of 250 million joules?? Forgive me, but I am not a physics major but a finance guy. Havent' done...
18. ### Measuring energy capture of river turbine

Yeah, i was kind of ignoring turbine efficiency in this case or just assuming 100 percent. I was wondering if it was correct to use the same equation of force times distance. I understand in the dam situation it falls 30m before turning the turbine, but what is the distance used in a river flow...
19. ### Measuring energy capture of river turbine

I understand that work done if we have (510,000 Kg or 5,000,000 N) of water falling 30 meters (like in a dam) would just be 5,000,000N * 30m= 150,000,000 Newton meters. But how would one measure the work captured by a turbine for a river that say travels 50km/h. I guess assuming the same mass...
20. ### Water cannon toy and pressure

@ Drakkith - ok thanks for your efforts. If anyone else has thoughts on this I would appreciate. Thank you in advance.
21. ### Water cannon toy and pressure

@ Drakkith - thanks so much for the reply. So the next query is, Given a set force and size of the cone (volume wise), we can can actually increase the pressure to almost any reasonable pressure (i.e. 500 Kpa?) by just making the tappering part more narrow and/or make the opening smaller...
22. ### Water cannon toy and pressure

I have this toy I bought for my daughter. It is called a Geyser Water Cannon and supposedly it works using the Venturi effect. Basically it's a 2 foot cone that starts out with a wide diameter (1 foot) and narrows to about 1 inch - with openings on each end. When you pull down or push down...