Welcome to PHY 121 Blog Help. Here's how it works. For each homework question and lab report we will make a post, this will probably contain a few tips on what the problems are about and how to solve them. If you are stuck on something then instead of emailing us directly you should post a comment in reply to the relevant post. We will try to guide you through tough points and help you understand the problems and the concepts behind them.
Friday, November 12, 2010
Ch 11_3 #2
Use a continuity equiation first to find velocity at point 2 (be careful there are 2 outgoing pipes), then use Bernoulli's principle to find pressure.
14 comments:
Anonymous
said...
I don't know what to do to find the velocity of the pope since there are two. I've tried a few things and they aren't working. somebody please point me in the right direction.
After I caluculated V2 from the equation A1*V1=A2*V2 I'm not sure where to go from there. Using Bernoullis equation and canceling out the height part of the equation, I'm getting a very large negative P2 value that's not getting accepted.
There are already enough hints in comments you just have to put them together: as one person said there are 2 pipes so the velocity V2 is calculated using the areas of 2 pipes. Then use Bernoulli's equation. Does the height change?
Professor, I think you're being a little too hard on us since it's clear that we need more direction and all this material is new to us. I've made a serious attempt at the problem and stated that after I got an answer for V2 and height is neglected I'm still getting the wrong answer using Bernoulli's equation. It would be helpful if instead of just repeating what's already written if you could provide additional hints or places in the problem where we could've went wrong.
I think you are on the right track but you have to clarify what you do not understand or what is not clear saying "I do not have a clue" does not allow me to help you effectively. It looks like you got it but probably something went wrong with unit conversion
The problem asks question about pressure so you need to make sure that you got velocity part correctly. Since you have 2 tubes coming out is their total cross section larger or smaller that the original one? Is velocity for one of the outgoing tubes is greater or less than the velocity for the incoming tube? Asses if you answer if it makes sense. At least it should be of the same order.
The final answer is asked to be entered in kPa that means if you converted 50 kPa to Pa i.e. 50000 you have to divide the final number by 1000 again to get kPa
14 comments:
I don't know what to do to find the velocity of the pope since there are two. I've tried a few things and they aren't working. somebody please point me in the right direction.
I mean pipe, not pope
there are 2 pipes...calculate using the 2 areas of the 2 pipes the water goes into
After I caluculated V2 from the equation A1*V1=A2*V2 I'm not sure where to go from there. Using Bernoullis equation and canceling out the height part of the equation, I'm getting a very large negative P2 value that's not getting accepted.
i dont understand this at all, can you post a step by step guide on how to solve it
this is impossible is any one gonna help
This entire chapter has been impossible.
try 12
There are already enough hints in comments you just have to put them together: as one person said there are 2 pipes so the velocity V2 is calculated using the areas of 2 pipes.
Then use Bernoulli's equation. Does the height change?
Professor, I think you're being a little too hard on us since it's clear that we need more direction and all this material is new to us. I've made a serious attempt at the problem and stated that after I got an answer for V2 and height is neglected I'm still getting the wrong answer using Bernoulli's equation. It would be helpful if instead of just repeating what's already written if you could provide additional hints or places in the problem where we could've went wrong.
I think you are on the right track but you have to clarify what you do not understand or what is not clear saying "I do not have a clue" does not allow me to help you effectively.
It looks like you got it but probably something went wrong with unit conversion
The problem asks question about pressure so you need to make sure that you got velocity part correctly.
Since you have 2 tubes coming out is their total cross section larger or smaller that the original one? Is velocity for one of the outgoing tubes is greater or less than the velocity for the incoming tube?
Asses if you answer if it makes sense.
At least it should be of the same order.
The final answer is asked to be entered in kPa that means if you converted 50 kPa to Pa i.e. 50000 you have to divide the final number by 1000 again to get kPa
Thankyou all your comments really helped and I got it!
Post a Comment