Was that a Maths exam? (1 Viewer)

[addikaye03]

this is making me regret not picking physics, sigh, if only i knew it was a whole lot of math

Isn't that the common perception of physics from exterior?

 

[Phoenix Fury]

Apparently not cos if I had have known how maths based the HSC exam was I would never have picked it.

 

[cutemouse]

I find it amazing that many people believe that it's impossible to do such calculations presented in the 2009 HSC Physics paper without using a calculator.

May I repeat again that in HSC level Physics you can be a decimal or so off and still get the marks PROVIDED THAT YOU SHOWED ALL WORKING.

I find it easier not using a calculator, if you find it easier using a calculator, then good for you. I don't like using calculators obviously, I don't know why people have such a problem with that. It's just personal preference... you don't see me having a go at people for actually using a calculator.

Yeah, I doubt too many people could do 0.866 x 1.6x10^16 in their heads. Nor would you be able to do the electron motion question. Nor Kepler's Third Law.

Probably not. But everybody has different preferences.

 

[biopia]

I have to play the devils advocate lol.
Fair enough that you can multiply the high indices, and exact angles. I just can't get over the example you gave haha. If you took the root of 69 as being "about 8", you would be way off in the final answer (considering it's 8.31 - 2dp). It just seems that the error in that case cannot be marginalised.

I am not getting up you or anything. I get the other stuff. Just not that ^.

 

[untouchablecuz]

That was uncalled for.

if you can survive w/o a calculator, its your own business

sorry about having a go at you

goodluck with everything

(nb: no sarcasm intended)

 

[random-1005]

I find it amazing that many people believe that it's impossible to do such calculations presented in the 2009 HSC Physics paper without using a calculator.

May I repeat again that in HSC level Physics you can be a decimal or so off and still get the marks PROVIDED THAT YOU SHOWED ALL WORKING.

I find it easier not using a calculator, if you find it easier using a calculator, then good for you. I don't like using calculators obviously, I don't know why people have such a problem with that. It's just personal preference... you don't see me having a go at people for actually using a calculator.


Probably not. But everybody has different preferences.

lol, i bet the markers will have a laugh at your paper.

Marker: "hey look at this smartass wanker, he cant even use a calculator, got the answer wrong, better take marks off for being arrogant"

you are too good for a calculator?

lol, if i was a marker and i saw some wanker trying to do complex multiplications in their head i would tell them to fuk off and give them zero

 

[cutemouse]

lol, i bet the markers will have a laugh at your paper.

Uhh no they wont because judging by everyone's answers here I got the same answer.

you are too good for a calculator?

No... I can't use one (ie. not good at using one). I thought you would've established that by what I've said.

complex multiplications

Complex numbers in Physics??? No way ... I thought I'd have some fun there.

 

[random-1005]

Uhh no they wont because judging by everyone's answers here I got the same answer.



No... I can't use one (ie. not good at using one). I thought you would've established that by what I've said.


Complex numbers in Physics??? No way ... I thought I'd have some fun there.

you should go back to yr 8, lol using a calculator, put brackets, type what you want, close, press equals, so much easier than estimating.

k
smartass, now obviously there is no way to check that you dnt use a calculator, but what is

(0.984^3) /(2.46^2) smarty pants, to 4 deci place

 

[Aerath]

Hmmm, how did you do the length contraction in your head?

 

[random-1005]

Hmmm, how did you do the length contraction in your head?

he uses a calculator, he is wanking mate, lol jim asshole, are you that desperate for attention that you need to bullshit about not needing a calculator

 

[addikaye03]

Well technically, you should go to the greatest amount of decimal places given in the Q, e.g. speed of particle is 0.899c, length is 0.8. you go to 3 d.p

So my Q follows, how do you go to 3dp+?

 

[cutemouse]

Hmmm, how did you do the length contraction in your head?

The speed was like 0.99999c wasn't it? I don't remember the rest length.

I don't see what's so hard about it. (0.99999)^2 is obviously going to be a little bit less than 0.99999 (I'd guess that it'd be about 0.99998 or 0.99997).

And then taking the square root would be the easy part.

 

[cutemouse]

Well technically, you should go to the greatest amount of decimal places given in the Q, e.g. speed of particle is 0.899c, length is 0.8. you go to 3 d.p

So my Q follows, how do you go to 3dp+?

No, technically you should go by the greatest amount of significant places given in the data. ie. Since you are given that c=3*10^8 you can only go to 1 sig fig, as far as I know (even though you were given 0.99999c).

But at HSC level they don't really care (unless it's for mass defects in Q2Q etc).

 

[addikaye03]

The speed was like 0.99999c wasn't it? I don't remember the rest length.

I don't see what's so hard about it. (0.99999)^2 is obviously going to be a little bit less than 0.99999 (I'd guess that it'd be about 0.99998 or 0.99997).

And then taking the square root would be the easy part.

I'm sorry, but that is fucking bullshit. Obviously you're serious.

Ok so then you go 1-(0.99999)^2= 0.00002

So now, whats the square root of 0.00002? Explain to me how you would do that?

 

[cutemouse]

I'm sorry, but that is fucking bullshit. Obviously you're serious.

Ok so then you go 1-(0.99999)^2= 0.00002

So now, whats the square root of 0.00002? Explain to me how you would do that?

What is BS?

0.00002 = 0.2*10^-4

You know that \sqrt(2) is about 1.41 and sqrt of 10 is about 3.2 ... So \sqrt(0.2) is approx. 1.41/3.2 and then just divide by 100 since \sqrt (1/10000) = 1/100

So \sqrt(0.00002) is about 1.41/3.2 * 1/100 which is about 0.4 *10^-2 = 4*10^-3. How much was I off by?

NB: I did 1.41/3.2 by working out how many times 3 goes into 14, which is obviously a little more than 4 times, hence I arrived with 0.4

Obviously if I was doing this myself (eg. in an exam) I would do most of this in my head without writing down my thought. And do note that I am wrong sometimes (like how ppl mess things up occasionally when using a calculator), so it's not perfect, but good enough for HSC Physics IMO.

 

[biopia]

:/

I'd be willing to bet there are less errors when using a calculator, but hey, if you're used to it...

 

[cutemouse]

Coming to think of it a bit more, here's the actual method that I used in the HSC exam.

0.00002 = 20*10^-6

sqrt20 is about 4.5 (since 16*1 1/4 = 20 and \sqrt16=4 , and \sqrt(5/4) is about 2.2/2 = 1.1)

and 1/10^6 = 1/10^3

(NB: \sqrt5 is a little bit more than 2.2)

so simply \sqrt(0.00002) = 4.5*10^-3

 

[Aerath]

Well, unfortunately for you, 4.5 x 10^-3 x the length (1.7x10^5), does not give you the 760.26 light years (or even 760) required. It gives you 765.

 

[cutemouse]

Well, unfortunately for you, 4.5 x 10^-3 x the length (1.7x10^5), does not give you the 760.26 light years (or even 760) required. It gives you 765.

*sigh* ....as I said earlier at HSC level it doesn't matter aslong as you've shown all working...

 

[random-1005]

*sigh* ....as I said earlier at HSC level it doesn't matter aslong as you've shown all working...

\


whats your student number??, markers, when you see this idiots paper give him zero for calculations, LOL, yr 12 and cnt even use a calculator, they make calculators for a reason knob, so twats like you dont guess answers, all you need are brackets to minimise calculator mistakes but instead mister noob wants to show off about how mad he is doing all this shit in his head, i hope you get lowest mark in the state prick, teach you for showing off.

"ill just show my working and then guess the final numerical answer"

LOLOLOLOLOL
NOOOOOOOOOOOOOOOOOOOOOB!