[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]

2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

File: 140 KB, 1200x800, 1284061356650.jpg [View same] [iqdb] [saucenao] [google]

noko Wed Oct 27 20:48:15 2010 No.1961545 [Reply] [Original]

a 3kg object has a velocity of (6i^ -1j^) m/s. What is the kinetic energy at this moment?

>>	Anonymous Wed Oct 27 20:50:15 2010 No.1961553 55

>>	sage sage Wed Oct 27 20:50:15 2010 No.1961550 1/2mv^2 v = the square of 37

>>	Anonymous Wed Oct 27 20:50:15 2010 No.1961555 Come on dude, that's in your textbook

>>	noko Wed Oct 27 20:51:15 2010 No.1961557 DUDE I keep getting 55, and the book says 60. HOW IS IT 60?!

>>	Anonymous Wed Oct 27 20:52:15 2010 No.1961559 File: 65 KB, 807x400, booster.jpg [View same] [iqdb] [saucenao] [google] Post some more pics OP and I'll give you an unlimited source of kinetic energy

>>	noko Wed Oct 27 20:53:15 2010 No.1961562 File: 40 KB, 453x604, 1284060121332.jpg [View same] [iqdb] [saucenao] [google] ok I'll keep posting until someone explains... I GUESS

>>	Anonymous Wed Oct 27 20:55:15 2010 No.1961572 >>1961557 mass actually = 3.25?

noko Wed Oct 27 20:56:15 2010 No.1961574
File: 192 KB, 448x598, 1284060239831.jpg [View same] [iqdb] [saucenao] [google]

The only way I've been able to manipulate the numbers to get 60 is 3(6.1^2 (Pythag) + 1)^2 / 2

But honestly I thought I was understanding it, and then I got to this question and I got the answer wrong. Ehhh

>>	Anonymous Wed Oct 27 20:57:15 2010 No.1961579 >>1961574 did you go to the book website to check for errata?

>>	Anonymous Wed Oct 27 20:58:15 2010 No.1961580 most likely erroneous OP

>>	Anonymous Wed Oct 27 20:59:15 2010 No.1961581 name of girl

>>	OP Wed Oct 27 21:00:15 2010 No.1961589 File: 33 KB, 420x500, 1284061014653.jpg [View same] [iqdb] [saucenao] [google] I'm thinking maybe use the Scalar dot product to find the ABCos?

>>	OP Wed Oct 27 21:03:15 2010 No.1961598 File: 20 KB, 450x600, 1237681174590.jpg [View same] [iqdb] [saucenao] [google] Shameless bump

>>	Anonymous Wed Oct 27 21:04:15 2010 No.1961600 name of girl in ops pic?

>>	Anonymous Wed Oct 27 21:05:15 2010 No.1961606 File: 36 KB, 364x366, dangedmiracle.jpg [View same] [iqdb] [saucenao] [google] >>1961545 I have no idea how OP is getting a different answer, however I would like to know the name of the girl in this photograph

>>	OP Wed Oct 27 21:06:15 2010 No.1961608 File: 40 KB, 600x800, 1237683101554.jpg [View same] [iqdb] [saucenao] [google] I need to know why the answer is 60 Joules to my original problem. I'm going fucking crazy. I have a quiz tomorrow WTF.

>>	weirdo Wed Oct 27 21:07:15 2010 No.1961612 it is 60 because there is only 1 significant figure

>>	OP Wed Oct 27 21:07:15 2010 No.1961614 File: 163 KB, 932x1200, 1237949090584.jpg [View same] [iqdb] [saucenao] [google] >>1961606 If you know why the answer is 60J you should tell me :).

>>	Anonymous Wed Oct 27 21:08:15 2010 No.1961617 >>1961612 i can live with that, but that's super gay.

>>	OP Wed Oct 27 21:09:15 2010 No.1961619 File: 179 KB, 375x500, 1237681145040.jpg [View same] [iqdb] [saucenao] [google] >>1961612 No, it is actually 3.00kg.

>>	Anonymous Wed Oct 27 21:09:15 2010 No.1961620 File: 111 KB, 320x480, ohisee.jpg [View same] [iqdb] [saucenao] [google] >>1961612

>>	OP Wed Oct 27 21:10:15 2010 No.1961623 File: 56 KB, 480x640, 1237681404981.jpg [View same] [iqdb] [saucenao] [google] and 6.00 and 1.00

>>	Anonymous Wed Oct 27 21:10:15 2010 No.1961626 >>1961619 thanks for posting that 21 posts after your original one. anything else you left out?

>>	weirdo Wed Oct 27 21:10:15 2010 No.1961628 >>1961619 >>1961623 well then i do not know

>>	Anonymous Wed Oct 27 21:10:15 2010 No.1961629 FUCKING FAGGOTS HNGGGG

>>	OP Wed Oct 27 21:11:15 2010 No.1961632 File: 41 KB, 450x600, 1237681822403.jpg [View same] [iqdb] [saucenao] [google] DUDE /sci you guys are like the smartest people I know... don't let me down now!

>>	OP Wed Oct 27 21:13:15 2010 No.1961640 File: 782 KB, 2136x3216, 1239934647127.jpg [View same] [iqdb] [saucenao] [google] Will deliver if someone gives me a better answer than sigfig BS.

>>	Anonymous Wed Oct 27 21:13:15 2010 No.1961643 The only reason it would be 60 is due to using 1 significant figure. Then it obviously rounds to 60. If you use 2 sig figs it is 56, and 3 it is 55.5

>>	Anonymous Wed Oct 27 21:14:15 2010 No.1961648 >>1961643 yep books wrong bro deal with it

>>	Anonymous Wed Oct 27 21:14:15 2010 No.1961647 >>1961632 heres what you do OP 1. Get a good night's sleep 2. Arrive before class starts 3. Ask teacher why your answer is different than the books 4. ????? 5. Profit? 6. Profit

>>	Anonymous Wed Oct 27 21:15:15 2010 No.1961651 >>1961632 garbage in garbage out

>>	OP Wed Oct 27 21:16:15 2010 No.1961656 File: 23 KB, 360x480, alt_0494.jpg [View same] [iqdb] [saucenao] [google] Yeah, I should just move on.... thanks anyways guys... I guess I should just trust myself more...

>>	Anonymous Wed Oct 27 21:17:15 2010 No.1961661 >>1961656 ist understandable. the book can shake your confidence like crazy.

>>	Anonymous Wed Oct 27 21:18:15 2010 No.1961663 File: 193 KB, 442x298, infiniterevup.png [View same] [iqdb] [saucenao] [google] >>1961656 I believe we were promised a name, OP

>>	OP Wed Oct 27 21:18:15 2010 No.1961667 File: 35 KB, 500x709, 152Z7833copy.jpg [View same] [iqdb] [saucenao] [google] I might be asking for some more help later, so I'll just leave this here.

biochemist !yOO9L7sT1k Wed Oct 27 21:59:15 2010 No.1961811

1) Find velocity squared using Pythagorean Theorem
6^2+1^2=37
v^2=37

2) KE=1/2mv^2
KE=1/2*3kg*37m2/s2
KE=55.5J

3) The problem limits you to one sig-fig because the objects mass is only known to one sig-fig. Thus we must express our answer as 60J

>>	Anonymous Wed Oct 27 22:00:15 2010 No.1961817 >>1961811 this was already covered. read thread first.

Anonymous Wed Oct 27 22:21:15 2010 No.1961912
File: 123 KB, 375x500, 1287547979441.jpg [View same] [iqdb] [saucenao] [google]

KE = (1/2)mv^2
m = 3 kg
v = (6i - 1j) m/s

Equilavent to Phythagorean Theorem. Remember these are vector components. So they're treated as velocity in the directions. (Sorry it's hard to explain)
c^2 = a^2 + b^2
v^2 = vi^2 + vj^2
v^2 = 6^2 + 1^2 = 37

KE = (1/2) m v^2
KE = (1/2) 3 (37) = 55.5 J

You can take the magnitude to say that ONE direction force, then v = sqrt(6^2 + 1^2).
But you're going to square it anyway.

The answer is 60 J?

You must have typed or wrote down the question wrong. It might have to be the vector components. Please look at it again since I believe this is the correct method.

sincerely,
M.E.

>>	Anonymous Thu Oct 28 00:44:15 2010 No.1962508 Fucking. Tits.

Advanced search
Text to find
Subject [?]Search by post subject. Leave empty for any.
Username [?]Search for user name. Leave empty for any user name.
Tripcode [?]Search for tripcode. Leave empty for any.
Email [?]Search by email. Leave empty for any.
Filename [?]Search by image filename. Leave empty for any.
From Date [?]Enter what date to start searching from. Format is YYYY-MM-DD
To Date [?]Enter what date to start searching until. Format is YYYY-MM-DD
Image hash
Search in	All Posts OPs Only
Deleted posts	Show all posts Show only deleted posts Only show non-deleted posts
Internal posts	Show all posts Show only internal posts Show only archived posts
Order	New posts first Old posts first
Capcode	All Posts Only by Users Only by Mods Only by Admins Only by Developers
Results	Posts Threads
Action	[ Simple ]