calculations (1 Viewer)

[sweet_chick]

can anyone remember what they got for calculations. I think i got thwm all wrong i was just getting strange answers. If i was expecting a large answer id get a small one. I do 4u maths so i usually dont get simple calculations like that wrong.

 

[ying123123]

wat caculation?
for which question
i can only remember qeustion 1
gramner moon some shit
t=6.11*10power of 5
not sure if its right

 

[richz]

ye that rings a bell and also v=10000m/s (around there)

 

[sweet_chick]

what about something where you had to calculate current i remember writing amps for something?

 

[richz]

i got 220A, around there

 

[All_Saints]

can anyone remember what they got for calculations. I think i got thwm all wrong i was just getting strange answers. If i was expecting a large answer id get a small one. I do 4u maths so i usually dont get simple calculations like that wrong.

Well i remember doing the last calculations..
u had to equate qvbsin0=mv^2/r
and sub the m value in p=mv... then use the charge of a proton which is 1.602*10^-19 to get the momentum

to find the mass of the proton u divide the momentum by the velocity...

to find the rest mass... use the m(v) value in part two and use the mass dilation formula..

 

[richz]

well, ur wrong

 

[Abtari]

no.. he isnt.

 

[richz]

no.. he isnt.

Well i remember doing the last calculations..
u had to equate qvbsin0=mv^2/r
and sub the m value in p=mv... then use the charge of a proton which is 1.602*10^-19 to get the momentum

to find the mass of the proton u divide the momentum by the velocity...

to find the rest mass... use the m(v) value in part two and use the mass dilation formula..

ye, ok, he is kinda rong becuz he rote sin0 which is eql to 0 and so p=0 and thats rong

 

[Haku]

i got 220A, around there

yea i got like 221.36 or 220.36, there abouts.

what did u get for the charge question? magnitude and sign

 

[richz]

that was tricky, i forgot, but i think the charge was negative, kinda guessed. heres my logic, well the electric field is going towards the negative, if the particle is negative it would attract to the positive but due to the electric field it pushes the particle towards th -ve so i thut it was negative. if it was +ve it would attract to the -ve and since the electric field was going towards that the particle would not be stattionary, becuz it wud push it further towards the -ve. To work out the charge i equated qE=F and F was the weight force, it was sumthing *10^-7 i think.

 

[ying123123]

is taht the question witht he parrel plates?
can really remember
second quesiton i think u use E=V/d
the last qesution like u use f=mg and F/E=q
had a guess dont think was was right had no idea of the charge so i just said it was positive

 

[richz]

yeah, it was very wierd, i dont even know how do u work out the sign, i just took a stab, made up some bs, as in my above post

 

[Shael]

that was tricky, i forgot, but i think the charge was negative, kinda guessed. heres my logic, well the electric field is going towards the negative, if the particle is negative it would attract to the positive but due to the electric field it pushes the particle towards th -ve so i thut it was negative. if it was +ve it would attract to the -ve and since the electric field was going towards that the particle would not be stattionary, becuz it wud push it further towards the -ve. To work out the charge i equated qE=F and F was the weight force, it was sumthing *10^-7 i think.

I figured it like this.. the particle is in mid air and there are two forces acting on it, one being gravity pulling it down, and the other from the electric field - depending on what sign the charge was. I said the charge was positive so it would repel from the positive charged plate from below it. Thus making the particle stay in the middle, because the gravity and repeling cancels it out.

Also, All_Saints method is correct. xrtzx, by sin0, he/she meant sin(theta). And if I remember correctly, theta = 90 degrees, therefore it was just 1 and you didnt need to worry about using sine in the equation.

 

[richz]

I figured it like this.. the particle is in mid air and there are two forces acting on it, one being gravity pulling it down, and the other from the electric field - depending on what sign the charge was. I said the charge was positive so it would repel from the positive charged plate from below it. Thus making the particle stay in the middle, because the gravity and repeling cancels it out.

Also, All_Saints method is correct. xrtzx, by sin0, he/she meant sin(theta). And if I remember correctly, theta = 90 degrees, therefore it was just 1 and you didnt need to worry about using sine in the equation.

yes, that sounds logical.

ps i wasnt saying he was totally rong, i just thut he rote sin0 which is =0 so then he couldnt get p

 

[jake2.0]

Well i remember doing the last calculations..
u had to equate qvbsin0=mv^2/r
and sub the m value in p=mv... then use the charge of a proton which is 1.602*10^-19 to get the momentum

to find the mass of the proton u divide the momentum by the velocity...

to find the rest mass... use the m(v) value in part two and use the mass dilation formula..

i put mg + qvbsin0 = mv^2/r, cause the weight force is also acting on the proton

i think thats right cause when i evaluated the rest mass it was pretty much the same as on the data sheet

 

[king_of_boredom]

didnt anyone else find q16 not enough working space? finding the orbital radius of ganymede.....i thought required more than four lines.

 

[powerhouse]

Yeah, I found the T and R of Io first, then used the t^2 / r^3 = t^2 / r^3 relationship to find the radius of Ganymede seeing as how we know the period of it as 4 times that of Io.

I had a weird answer for the period and I think I had the radius at about 600,000km but I'm uncertain about that. Using 600,000ish as my radius I found the velocity to be 30,000km/h, so I'm unsure about tha too.

 

[redd]

would u guys agree the calculation questions were especially hard this year, many equations such as using the momentum formula was never used before i dont think.

oh and also i remember using centripetal force formula somewhere,

pfft im prolly wrong

 

[sweet_chick]

yea alot of ppl in my class had no idea cause alot of the questions reguired alot of manipulation of formula and they are all pretty stupid