All energy has been destroyed.
|How much energy is lost in an internal cubustion engine?||Anonymous|
Wed. 17, Oct 2007, 21:49
|By "lost" do you mean gone, non-existent?|
No energy is lost!
Is some (a lot) of the energy not transfered to the drive shaft? Yes!
Thu. 18, Oct 2007, 08:41
|How can energy lost in the form of heat be recycled into a reusable form of energy for a system?||Soler, Lynn|
Wed. 17, Oct 2007, 22:27
|It depends on lots of factors. What is heating up, for instance.|
I have a wood burning stove at home. It is really amazing to watch. When I get the two vents set just right, the wood sits on the bottom and the flames hoover about five inches above the wood! The flames are more like jets at that point. It is wild to see and hear!
My stove "recycles" the hot combustible gasses (and small floating fragments) via convection and redirects these gases over the wood where the air is hot. The gasses burn and recycle until it is cool enough to exhaust itself nearly emission free (2grams emission / hour.) When my stove is running most effeciently the "smoke" out of the stack is nearly clear (transparent!) In this setting one load of cheap, pine 2x4's can burn for up to 10+ hours!
This is just one example of attempting to re-capture energy and use as much as possible.
(P.S. I also put a large pot of water on the stove's top surface. It evaporate water and adds humidity to Denver's dry air in my house. Sometimes, I even bake some rolls!)
Thu. 18, Oct 2007, 08:49
|In workbook page 6, it asked for the "standard deviation". How do I find the standard deviation and what does it mean in energy?||Anonymous|
Fri. 26, Oct 2007, 23:36
|The standard deviation is asked in regards to the angle, not the energy.|
It might even be better to find simply sinθ and its standard deviation rather than θ.
If you create a table of values in a spreadsheet in cell A1 through A3, then you can find the average by entering this in cell A4
And type this in cell A5 for the Standard Deviation:
Sat. 27, Oct 2007, 06:11
|The energy lab is a three week lab correct? Is the post lab really due for the lab this week before class or will that deadline be extended?||Anonymous|
Tue. 30, Oct 2007, 16:28
|Oops, my biff.|
The deadline is now fixed for the week of November 5th plus one day. :)
Wed. 31, Oct 2007, 08:34
|Lots of students have asked about how to find a Potential Energy equation that Data Studio can use. Data Studio can only measure x. It can't measure h which is needed for U = mgh. Can I produce a huge hint?||Howey, Douglas|
Mon. 17, Mar 2008, 14:15
|Okay, here it is:||Douglas|
Mon. 17, Mar 2008, 14:20
|Lots of students have asked about how to measure sin(θ) for the incline. We need to know that value (sin(θ)) for the new U equation. Is there a humungous hint?||Howey, Douglas|
Mon. 17, Mar 2008, 14:16
|Use the Vernier plunger to measure the h's seen below.||Douglas|
Mon. 17, Mar 2008, 14:21
|I am a little confused on question 6 in the postlab. What do we do with acceleration? I can not think of an equation to use to figure out the height.||Cooper, Ryan|
Mon. 27, Oct 2008, 18:45
|Try to go back to the Data and Graphs lab. We created an incline there, found the acceleration and had a relationship between acceleration and height of riser block. Or, draw a free-body diagram to find the acceleration along the incline. (Sin(θ) is involved.)||Douglas|
Tue. 28, Oct 2008, 07:54
|I am confused about question # 1 on the post lab quiz. When you say the 'levelness' do you mean what is the best way to determine when the slope of the glider track is zero? Can you please clarify the question for me?||Anonymous|
Tue. 28, Oct 2008, 12:17
|Yes, is the track level? Is the slope of the track 0? How can you test for this condition?||Douglas|
Wed. 29, Oct 2008, 08:30
|for question 2 in postlab. Does Kinetic enery go from max to zero as the car start from lowest and stop at its highest motion||pham, chuong|
Tue. 07, Jul 2009, 15:35
|I can't answer that as that is a main point of the experiment. If KE is 1/2 m*v*v, then what if v is zero, what is KE? What is v at highest point reached by cart?||Douglas|
Tue. 07, Jul 2009, 16:08
|In our lab, we were wondering if we should use the same coordinate system for the trip up and the trip down. We wanted to make the work of friction negative in both directions. Thank you.||Anonymous|
Thu. 28, Oct 2010, 03:41
|Use the same coordinate system for both directions.||Douglas|
Thu. 28, Oct 2010, 04:05
|Hello Douglas, |
Question 6 of post-lab provides enough information to calculate total height; we are asked to calculate the height of the block. We are told that the block is placed under the leg. Considering that total height consists of the height of the block + the height of the leg, shouldn't we be given the height of the leg in order to be able to determine the height of the block? Thank you.
Sun. 31, Oct 2010, 12:02
|Without the block the track is supposed to be level while sitting on the table. With the block, the only difference in height from one support leg to the next is the block. The support legs could be 2 cm or 2 m high and the block would still provide the same angle.||Douglas|
Mon. 01, Nov 2010, 03:13
|Our potential energy does not start at zero. The equations have been checked. Any ideas on this?||Anonymous|
Sun. 15, Jul 2012, 22:34
|See the third video at the energy webpage. It covers this in detail.||Douglas|
Mon. 16, Jul 2012, 04:45