OpenStudy (kittykat):

Physics Questions 4

1 year ago
OpenStudy (kittykat):
1 year ago

OpenStudy (kittykat):

I was using the formula Ep=Ek , q(V/d)= 1/2mv^2 , but not getting the answer anything wrong ? @Evoker

1 year ago
OpenStudy (kittykat):

@osprey

1 year ago
OpenStudy (agent0smith):

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elewor.html \[\large W = q \Delta V = \Delta KE\]since the final speed is zero\[\large q \Delta V = \frac{ 1 }{ 2 } m v^2 \]plug in the charge of an alpha (2 times electron), and the mass (4 times the atomic mass unit)\[\Large 2(1.602*10^{-19}) (1.2*10^2) = \frac{ 1 }{ 2 } (6.64×10^{−27}) v^2 \]

1 year ago
OpenStudy (kittykat):

thats what I did didnt get the answer

1 year ago
OpenStudy (kittykat):

I got 3 somthing that is not matching any of the choices

1 year ago
OpenStudy (kittykat):

what you get ?

1 year ago
OpenStudy (agent0smith):

You must have done some math wrong... http://www.wolframalpha.com/input/?i=2(1.602*10%5E%7B-19%7D)+(1.2*10%5E2)+%3D+%5Cfrac%7B+1+%7D%7B+2+%7D+(6.64%C3%9710%5E%7B%E2%88%9227%7D)+v%5E2

1 year ago
OpenStudy (kittykat):

Oh yea! lol sorry

1 year ago
OpenStudy (agent0smith):

lol no prob :)

1 year ago
OpenStudy (agent0smith):

Your original formula was wrong, though: q(V/d)= 1/2mv^2 there should be no d, just qV.

1 year ago
OpenStudy (kittykat):

oh so the distance they give is just an distraction ?

1 year ago
OpenStudy (agent0smith):

Yep :)

1 year ago
OpenStudy (kittykat):

can you help me with this one

1 year ago
OpenStudy (agent0smith):

Light travels slowest through the highest refractive index

1 year ago
OpenStudy (kittykat):

i'll get that to later but this other I just have no idea

1 year ago
OpenStudy (kittykat):

any idea?

1 year ago
OpenStudy (agent0smith):

Different wavelengths refract to different angles. Remember the Pink Floyd album cover... http://ep.yimg.com/ay/pandorasboxoc/pink-floyd-dark-side-of-the-moon-tapestry-wall-hanging-1.gif As for the last "Light travels slowest through the highest refractive index " just choose the highest index - glass at 1.5 - is the slowest

1 year ago
OpenStudy (kittykat):

should I just memorizr this ?

1 year ago
OpenStudy (kittykat):

oh its not B beacuse its refracts straight lines not defracts (waves) right ?

1 year ago
OpenStudy (agent0smith):

Yes, it's A. Refract, not diffract.

1 year ago
OpenStudy (kittykat):

Ok this one I am confused they just give one thing

1 year ago
OpenStudy (kittykat):

Do you wanna see the formula sheet ? that I use ?

1 year ago
OpenStudy (kittykat):

or you knwo the formulas ?

1 year ago
OpenStudy (agent0smith):

Sure. I think it's \(\large E = hf\) you need to use first... The E would be the given value for silicon, h is plancks constant, f is frequency. Then use \(\large c = f \lambda \)

1 year ago
OpenStudy (kittykat):

oh beacuse my formila sheet says W= E ? so E and W same thing ?

1 year ago
OpenStudy (agent0smith):

Yeah, remember that work done is equal to energy expended or supplied or w/e.

1 year ago
OpenStudy (kittykat):

wow okey yea got it ! thank you!

1 year ago
OpenStudy (agent0smith):

Welcome!

1 year ago
OpenStudy (kittykat):

also I was still confused about the physics pricipls quesiton like when thy ask you what the pricnicplas are used in this question how to comnbat that?

1 year ago
OpenStudy (agent0smith):

Yeah those ones are a little annoying, really. I don't really have a good way to explain it. Just try to figure out how you'd solve it, then try to match your method with things on the list of principles.

1 year ago
OpenStudy (kittykat):

hey u there can help me with another ?

1 year ago
OpenStudy (agent0smith):

sure, post a new question though

1 year ago
OpenStudy (kittykat):
1 year ago

OpenStudy (agent0smith):

I think you just need to convert the units TeV to J.

1 year ago
OpenStudy (kittykat):

wow that easy! I always get confused thinking I have to use some kind of a formula!

1 year ago
OpenStudy (agent0smith):

haha i thought so at first too... but eV are a unit of energy. Tera is... idk i forgot but google will know.

1 year ago
OpenStudy (agent0smith):

T is \(\large 10^{12}\) and then just plug in the electron charge \(\large 1.602*10^{-19}\)

1 year ago
OpenStudy (osprey):

An alpha particle is a helium nucleus. It has two positive charges. It has a nuclear mass of 4 protons. It has an initial kinetic energy of “half m v squared” as is often said. The field between the plates works against this kinetic energy, and decelerates the particle to zero speed. The principle of conservation of energy can be used in the form that the work energy supplied by the field between the plates is used to work to decelerate and thus convert the kinetic energy of the moving alpha particle. A load of number crunching later and the answer turns out to be A I've enclosed the grinding calculation in a powerpoint show as per. I wonder how many marks the question is worth ... I also wonder whether it would be worth everyone's while just to find away of uploading the entire paper you're looking at, constants, and marks and all.

1 year ago
OpenStudy (kittykat):

can you help me with this one ?

1 year ago
OpenStudy (agent0smith):

Time to make a brand new question @KittyKat as this is long enough

1 year ago
OpenStudy (kittykat):

yea sure

1 year ago