Physics question, ...machines... |
  |
 Feb 10 2005, 06:16 PM
Post
#1
|
|
 Shove it  Group: Member Posts: 496 Joined: Jan 2005 Member No: 91,641  |
On a recent Physics quiz we had this question:
"True or False: An ideal machine will have an efficiency greater than 100%" Now, my teacher was trying to see whether or not we knew that the energy you put into a machine will be equal to or less than the energy coming out of the machine. I got the answer right. However, a few people in my class are arguing that it was an unfair question because an ideal machine would have an efficiency greater than 100%. We think that my teacher should just omit the question because it can go either way. Would you answer true or false? |
|
|
|
|
Feb 10 2005, 06:18 PM
Post
#2
|
|
|
cb=bullshit. Group: Member Posts: 1,783 Joined: Feb 2004 Member No: 3,793 |
I'd circle both the answers. =]
|
|
|
|
|
Feb 10 2005, 06:20 PM
Post
#3
|
|
|
Shove it Group: Member Posts: 496 Joined: Jan 2005 Member No: 91,641 |
Smartass
 Our quizzes are on scantrons anyway so it would only count the first mark, which would be A (which was true) and it would be marked wrong. 
|
|
|
|
|
Feb 10 2005, 10:39 PM
Post
#4
|
|
|
cb=bullshit. Group: Member Posts: 1,783 Joined: Feb 2004 Member No: 3,793 |
I'd circle a and b.
|
|
|
|
|
Feb 10 2005, 10:41 PM
Post
#5
|
|
 :hammer: Group: Staff Alumni Posts: 9,849 Joined: Mar 2004 Member No: 7,700 |
Hey Hillary! Hilary?
Ahem. I'd bubble-in.. false. Because because.. how can you have more than 100% of your -- ah screw it. |
|
|
|
|
Feb 11 2005, 12:03 AM
Post
#6
|
|
 hi, my name is hillary Group: Member Posts: 352 Joined: Dec 2004 Member No: 76,591 |
*gasp* your name is hillary too?!
um.. i cant really help you out here because even though im in physics.. im not doing a very good job in there.. 
|
|
|
|
|
Feb 11 2005, 10:00 AM
Post
#7
|
|
 I can't believe its not "Ryan" Group: Member Posts: 1,981 Joined: Jun 2004 Member No: 21,368 |
A machine is only as efficient as the human that makes it, imagine if it was built on an assembly line, many humans many mistakes. Even with the ideal machine, it still will make errors and make it under 100%.
|
|
|
|
| *wind&fire* |
Feb 12 2005, 03:09 AM
Post
#8
|
|
Guest |
thats impossible to exceed 100% efficiency since there is such a thing as "conservation of energy"
|
|
|
|
|
Feb 12 2005, 05:27 PM
Post
#9
|
|
 ^ I might look scary but i'm the nicest person in cb! Group: Member Posts: 1,364 Joined: Feb 2004 Member No: 4,979 |
i dunno
i took physic AP in high school. and we never learn that question all we learn is the complicated stuff. |
|
|
|
| *AngelicEyz00* |
Feb 12 2005, 08:10 PM
Post
#10
|
|
Guest |
I'd pick false. My guess, is, ideally, I'd want a machine to be 100% efficient. And I doubt they can be more than 100%, so yeah. Seems like a trick question though...
|
|
|
|
|
Feb 18 2005, 09:38 PM
Post
#11
|
|
|
lAzN YiN YanGl Group: Member Posts: 376 Joined: Jun 2004 Member No: 20,905 |
If it could go more, then wouldn't that cause a new 100% causing each amount of energy put in to represent a lower percentage? Something similar to if you ever play a game where you level up, you need a certain amount of experience to level up the first time. But you can do the same amount and get less of a percent. Get it? woah..headache...
|
|
|
|
| *wind&fire* |
Feb 18 2005, 11:21 PM
Post
#12
|
|
Guest |
it cant even get up to 100%
Lenz's law states that the induced current always causes a motor effect, which opposes the original flux change that caused the generator effect... in other words when the motor effect is in place there will always be an opposing force... |
|
|
|
|
2 User(s) are reading this topic (2 Guests and 0 Anonymous Users)
0 Members: