Find the induced electromotive force (epsilon)

AI Thread Summary
The discussion revolves around calculating the induced electromotive force (EMF) in a scenario involving a slider moving along a contour at a 37-degree angle. The parameters provided include a slider speed of 0.16 m/s and a length of 0.14 m. Participants emphasize the need for a clearer problem description and legible diagrams to facilitate understanding. The complexity arises from needing to account for the changing area of the closed loop as the slider moves, particularly focusing on the triangular area formed by the angle. A specific instant when the line AC measures 14 cm is highlighted as critical for determining the EMF.
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it is something like this but instead of the rectalve contour iswith the angle 37 degree!https://www.physicsforums.com/attachments/114624 1. Homework Statement

the speed of the slide is 0.16 m/s
the length of the slide is 0.14 m
the angle of the contour is 37 degree

Homework Equations


inducted electromotoric force=-delta phi/delta time
phi=induction(B)*surface*cos alpha (alpha=0 degree)[/B]

The Attempt at a Solution

https://drive.google.com/file/d/0BxmarOZtFg5FdEJDWkNaRnVZX00/view?usp=sharing [/B]
 
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1. Your problem description is too vague. "something like this" is not good enough. There's no way to know what your 37° angle pertains to.

2. Your image of your attempt at solution is all but illegible (too dark, out of focus). If necessary, type in your solution and only provide images for diagrams.
 
gneill said:
1. Your problem description is too vague. "something like this" is not good enough. There's no way to know what your 37° angle pertains to.

2. Your image of your attempt at solution is all but illegible (too dark, out of focus). If necessary, type in your solution and only provide images for diagrams.
gneill said:
1. Your problem description is too vague. "something like this" is not good enough. There's no way to know what your 37° angle pertains to.

2. Your image of your attempt at solution is all but illegible (too dark, out of focus). If necessary, type in your solution and only provide images for diagrams.
 

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It looks like the slider will lose contact with the two arms of the contour immediately after it passes the points AC. Is that intended?

Since the rate of change of the area of the closed loop will change with time, the EMF will change with time, too. Is there a particular instant in time or position of the slider for which you need to find the EMF?

You need to take your time to thoroughly prepare your problem description so that others can quickly and easily understand the details.
 
The slider will continue to to slide (mayby it can stretch?? I don't know ,but I am pretty sure that's not the case here) we have explained before in class what happens in a rectangle contour (the surface becomes l*dt*v and dt is being simplyfied with dt down and epsilon becomes -Blv) this is the exact thibg but ibstead of the S=l*dt*v it is more complicated because we should find the surface of the triangle above (right triangle with 37degree abgle ) this surface + the surface of yhe rectanglr should give a surface which has an dt inside (this dt sbould the be simplified with the dt down and should give the answer but this is fifficult to get a firmula with only one dt (this is mostly a trigonometric exercisr) si pls help because I am really stuck (my teacher gave it only to me this exc. Causev I am the best in my class and i can't let her down)
 
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It looks like you want to find the EMF at the specific instant that the line AC is 14 cm in length. Suppose that at that instant that the two legs of the right angle triangle are x and y, with y being coincident with the line AC. How might you solve for x given the angle and value for y?

upload_2017-3-16_17-10-55.png


Then, what's the area of the triangle in terms of x?
 
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