Discus: What Are My Chances?: January 2003 Archive: Challenging physics problems for FREE PRACTICE TESTS
 By go get em on Monday, January 13, 2003 - 08:02 pm: Edit

ok everyone, i have received the 50 practice tests from this Indian kid in my school and im willing to give 5 free ones out to the person that solves these problems the quickest. just post your EMAIL or you can email me with your SN after you post your answers.

here are the problems.. each are worth 2 free practice tests. first one to get it wins. there are 4 different questions so here we go...

1) mass=784N , Volume=4.2m/s, A=3.2 m/s(squared)

2)Freq= 1200 rev/MIN, r=15 cm
Find the force, volume,acceleration and mass.

find the acceleration, volume, and frequency

Find the force, volume and acceleration

there they are... each right answer is worth two points and each points is a free SAT test mailed to your respective email address. I have the answers and will check to see if yours match mine. Finally a competition on these boards.

GOOD LUCK -alex

 By bump on Monday, January 13, 2003 - 08:05 pm: Edit

bumper

 By johnstone on Monday, January 13, 2003 - 08:14 pm: Edit

o man that would be great.. im off to work on these problems... thanx man

 By dedric on Monday, January 13, 2003 - 08:21 pm: Edit

im doing them now

 By dxiw on Monday, January 13, 2003 - 08:28 pm: Edit

i'm assuming these are all typo and volume is velocity...

1) Force=256N, R=5.51m, Freq=8.24rot/sec
2) Vel=4.2cm/s
3) Accel=5m/s^2 Vel=5m/s Freq=6.28rot/sec
4) Force=12600.2N Vel=502cm/s Accel=3150.05cm/s^2

dxiw@charter.net

these are off my head for now, later with a calc i'll do some more...

 By go get em on Monday, January 13, 2003 - 08:45 pm: Edit

finish number two with a calculator and you get all 8 practice tests... i have 50 of them that i can send in Microsoft word so if anyone else wants them then you can write ure answers in too, if you think it is wrong

 By dxiw on Monday, January 13, 2003 - 08:49 pm: Edit

I get any right?

 By dxiw on Monday, January 13, 2003 - 08:50 pm: Edit

ok, hold on...

 By go get em on Monday, January 13, 2003 - 08:50 pm: Edit

ok

 By go get em on Monday, January 13, 2003 - 08:51 pm: Edit

dxiw, what were your SAT scores and what science class are you taking at the moment?

 By Tuannguyen (Tuannguyen) on Monday, January 13, 2003 - 08:55 pm: Edit

Maybe you should make the questions harder... Doesn't seem challenging enough to even be a quiz, from what i've seen... Anyways, i don't want to review my notes to find out how to do those, so i pass...

 By dxiw on Monday, January 13, 2003 - 08:56 pm: Edit

2) Vel=4.2cm/s Ac=1.176cm/s^2 I can't find the mass from that info, and therefore can't get the force either, I guess just give me 1 test for #2 instead of 2...So e-mail me over the 7...

 By go get em on Monday, January 13, 2003 - 08:56 pm: Edit

i doubt that you can do them tuannguyen.

 By go get em on Monday, January 13, 2003 - 08:57 pm: Edit

what did yu get on your SAT dxiw and what is your present science class.

 By dxiw on Monday, January 13, 2003 - 08:57 pm: Edit

oh and my sat score is 1450 (I'm retaking soon) and I am taking multivariable/vector calculus. I am in AP Physics B, my first year in physics..

 By go get em on Monday, January 13, 2003 - 08:58 pm: Edit

ok, dxiw, give me your final answers in one post and you get the 7 tests... no one has gotten the answers yet so it looks like its all you.

 By dxiw on Monday, January 13, 2003 - 08:58 pm: Edit

my first physics class and if your wondering with the math i've taken calc ab,calc bc,ordinary diff eq.

 By dxiw on Monday, January 13, 2003 - 09:00 pm: Edit

1) Force=256N, R=5.51m, Freq=8.24rot/sec
2) Vel=4.2cm/s Acc=1.176cm/s^2
3) Accel=5m/s^2 Vel=5m/s Freq=6.28rot/sec
4) Force=12600.2N Vel=502cm/s Accel=3150.05cm/s^2

dxiw@charter.net

 By go get em on Monday, January 13, 2003 - 09:01 pm: Edit

does everyone agree with this man...????
it looks correct to me.
if anyone can correct him then he doesnt win.
if no one corrects you then you win( you have 10 minutes and then they will be sent.)

 By go get em? on Monday, January 13, 2003 - 09:02 pm: Edit

are you positive number 3 is correct?

 By dxiw on Monday, January 13, 2003 - 09:09 pm: Edit

I'm pretty sure...cause mass is 70 so 5g force would be 350N. thats means that the accel is 5m/s^2. Then since a=v^2/r then 5=v^2/5 so v=5m/s. Then for the frequency, V=2piR / T, so 5=2pi5/T, so T=2pi=6.28

 By go get em on Monday, January 13, 2003 - 09:15 pm: Edit

just explain to me how you obtained the other 3 answers. You are the unanimous winner of this competition. I just need to see how you got the answers. And the tests are yours to keep. This is kind of a big thing(7 practice tests!!!) so i have to be sure you got it right.

just write the work for the other 3 problems and they are yours.

 By go get em on Monday, January 13, 2003 - 09:26 pm: Edit

bump look up one post dxiw... u only have to do 3 problems more. this is just cuz i am a little reluctant to give away 7 whole tests when i can sell them and shitt. but i figured what the hell, ure a nice guy and you seem to be on target for a 1500 , and these tests should really help you out.

 By dxiw on Monday, January 13, 2003 - 09:28 pm: Edit

ok well.

all i did for all of them is use the following formulas:

V=2piR/T
A=V^2/R
F=MV^2/R=MA

V is velocity, A is acceleration, T is period, R is radius,M is mass

so
1) M=784N=80kg V=4.2 A=3.2
F=ma=(80)(3.2)=256N
3.2=4.2^2/R R=5.51m
4.2=2(pi)(5.51)/T T=8.24rot/sec

2) T=1200/min R=15
T=1200/min=20/sec
V=2pi(15)/20=4.2cm/sec
A=4.2^2/15=1.176cm/s^2

3) M=70kg F=350N R=5
F=MA so A=5m/s^2
A=V^2/R 5=V^2/5 V=5m/s
V=2piR/T 5=2pi(5)/T T=2pi=6.28rot/sec

4) R=80cm T=1rot/sec M=4kg
V=2pi(80)/1=502cm/sec
F=MA=M(V^2/R)=(4kg)(502)^2/80=12600.2N
A=V^2/R=502^2/80=3150.05cm/s^2

1) Force=256N, R=5.51m, Freq=8.24rot/sec
2) Vel=4.2cm/s Acc=1.176cm/s^2
3) Accel=5m/s^2 Vel=5m/s Freq=6.28rot/sec
4) Force=12600.2N Vel=502cm/s Accel=3150.05cm/s^2

 By go get em on Monday, January 13, 2003 - 09:29 pm: Edit

you will be getting them in 5 minutes.

 By dxiw on Monday, January 13, 2003 - 09:29 pm: Edit

sorry it took me a while to type it out, but yea I'm really dying to break that 1500 barrier and these really help me a lot. thanks.

 By go get them on Monday, January 13, 2003 - 09:41 pm: Edit

you will break the 1500 barrier, you dont need my help. someone as smart as you, i mean come on, 1450 is great for princeton

 By dxiw on Monday, January 13, 2003 - 09:47 pm: Edit

well I'm really going for a 1600 as I made an 800 in math on the real thing (and a 650v). But lately I've been reading alot and my verbal on practices is around 700-720V. I'm gonna keep practicing until I make like 750-800. Then sit for the real thing!

 By Anona on Monday, January 13, 2003 - 09:59 pm: Edit

why are you doing this kid's homework for practice tests whice a)probably don't exist. b)if they do exist are available online and c)really won't help you anyway.

 By dxiw on Monday, January 13, 2003 - 10:03 pm: Edit

just being nice =)

 By go get em on Monday, January 13, 2003 - 11:08 pm: Edit

dxiw, i am truly sorry that i can not give you the practice tests. I honestly thought that my Indian friend Gajan was going to let me give out the SAT's that he gave me. He is not though and has taken 40 of them away from me so now i am left with only 10. If i were you i would have cussed myself out because i really put you though some trouble in formulating those answers. You seem extremely bright and up to task with your schoolwork, and in general, life. I am really impressed by your reaction and i guarenttee and truly hope that you will get mid 1500's and possibly a 1600 on your next date with the SAT. Good luck and have a happy and healthy life... once again, i am very sorry. Good luck.

-mike

 By Pat57575 (Pat57575) on Monday, January 13, 2003 - 11:55 pm: Edit

ya, those problems were pretty crappy.

 By ss on Tuesday, January 14, 2003 - 12:05 am: Edit

in 1) volume in m/s ? that strange
v should be the velocity!

 By a on Tuesday, January 14, 2003 - 12:23 am: Edit

lol dxiw, nice job doing that shithead's homework

 By Fender1 (Fender1) on Tuesday, January 14, 2003 - 01:31 am: Edit

I especially loved the pasrt where he made you explain the work you did, but seriously, if he cannot figure those out, then its a wonder how he will get a decent grade in physics class

 By dxiw on Tuesday, January 14, 2003 - 05:05 pm: Edit

go get em - I knew you were full of it from the start, I just wanted to be nice and help you with your homework. Oh well, post back when you get it graded, I wanna see if I got a 100.

But dude, you should seriously learn this stuff, those only took me like 2 min. I'm not trying to brag I'm just saying thats easy stuff...

 By Weidamengxing (Weidamengxing) on Tuesday, January 14, 2003 - 07:48 pm: Edit

dude, I don't know if this is some kindda of cultural difference but in Chinese commonsense, if u really got something like 50 tests, u shall post it right here.

 By Tuannguyen (Tuannguyen) on Tuesday, January 14, 2003 - 07:53 pm: Edit

"But dude, you should seriously learn this stuff, those only took me like 2 min. I'm not trying to brag I'm just saying thats easy stuff..."

You're not bragging at all, those are so easy i think my little sister can do it. Actually, i've studied these so long ago the notes i took must be close to 2 years old. This guy just doesn't do his HW, he probably won't get into college if those questions challenge him.

 By Burberry (Burberry) on Tuesday, January 14, 2003 - 08:00 pm: Edit

hey hey, get off his case... i dunno how to do those problems either, and i get good grades in my high school... then again, i never took a "real" physics class. we just learned about astronomy...

 By nim on Tuesday, January 14, 2003 - 10:52 pm: Edit

ur pretty gay. i wonder how physics will help you in real life. oh no that dish is falling down with an accerlation of the net force of the blingwad....what a faggot