X-ray photon E?

[whyareyoureadingthis]

I think I put 25000.
Didn't know whether the electron speed was going to be the same or not, so I got it using KE=0.5mv^2. Was it the same or not?

[schnappy]

That entire a4 page is covered in writing on mine. I knew how to do it, I just kept getting different and spastic answers. I thought 24000ish would be way to high! wow I probably got the right answer but cross it off at some point Aw well, I'm quite confident on everything else. Not going to disappoint by looking at the 'answers'. I got concerned with the sound question, where the intensity dropped by 1/16. I couldn't evaluate the logarithm... I guess 58dB anyway. During my spare 30mins at the end I found a log button on my scientific calculator and was super happy fun times. I spent about 20 minutes of this x-ray energy question.

[bblovee]

I left it in scientific form: 2.48 x 10^4 since the only number they gave us was 600eV which has 3 sig figs.
But I don't believe vcaa is as pedantic on sig figs with physics as they are with chem

[Galvanic Cell]

If i did everything correct, but used the wrong speed (i used the stated speed from earlier), will i get any marks?

[Whatlol]

If i did everything correct, but used the wrong speed (i used the stated speed from earlier), will i get any marks?

yes you should get at least 1 mark for correct working out.

[3Xamz]

That entire a4 page is covered in writing on mine. I knew how to do it, I just kept getting different and spastic answers. I thought 24000ish would be way to high! wow I probably got the right answer but cross it off at some point Aw well, I'm quite confident on everything else. Not going to disappoint by looking at the 'answers'. I got concerned with the sound question, where the intensity dropped by 1/16. I couldn't evaluate the logarithm... I guess 58dB anyway. During my spare 30mins at the end I found a log button on my scientific calculator and was super happy fun times. I spent about 20 minutes of this x-ray energy question.

LOL good guess, answer was 58dB.

[Greggler]

reckon i could scrape a mark when i found both the momentum and de broglie wavelength of the x ray or whatever it was. just didnt apply it properly ><

[Whatlol]

reckon i could scrape a mark when i found both the momentum and de broglie wavelength of the x ray or whatever it was. just didnt apply it properly ><

hmm, i would like to think so since its worth 3 marks

[lachymm]

how the hell did i get 12240 eV

[Whatlol]

how the hell did i get 12240 eV

might of forgot the 2 when finding velocity?

[Droobasaur]

For some reason I decided to use frequency in my calculations and ended up with 26000 eV.
Close enough. I think I deserve full marks.

[Whatlol]

For some reason I decided to use frequency in my calculations and ended up with 26000 eV.
Close enough. I think I deserve full marks.

umm depends what frequency you found

[Chavi]

How many significant figures for full marks?
I left it as 24977 (or something like that) - instead of 2.5x10^4. Any problems>?

[Whatlol]

How many significant figures for full marks?
I left it as 24977 (or something like that) - instead of 2.5x10^4. Any problems>?

dont think it will matter to be honest. i thought physics doesnt penalise for not using significant figures?

[m@tty]

2 sf should be fine.

Only thing I've ever heard about significant figures in physics is that examiners get pissed if you write 587648233985462.1 instead of 5.87*10^(whatever)..

Usually 2 or 3 will suffice.