Blizzhackers

Home of the Dupe since 2001

* Login   * Register    * FAQ    * Search

Join us on IRC: #bh@irc.synirc.net (or Mibbit Web IRC)


MuleFactory


It is currently Thu Jul 24, 2014 1:59 pm


All times are UTC [ DST ]





Post new topic Reply to topic  [ 9 posts ] 
Author Message
 Post subject: Quick Physics Question
PostPosted: Wed Feb 03, 2010 6:27 am 
 
Banned
Banned
User avatar

Joined: Sun Nov 11, 2007 11:37 pm
Location: Claudeville
I'm taking an online test for Intro to Physics. (It's pretty easy) But this one stumped me. Maybe someone here can help.

36) A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the brakes were applied was

A) 1.2 m/s
B) 45 m/s
C) 30 m/s
D) 15 m/s
E) None of these

_________________
Image

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 6:42 am 
 
User
User

Joined: Fri Jan 23, 2004 2:02 am
My guess is C.

_________________
Image

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 6:45 am 
 
User
User

Joined: Fri Jun 16, 2006 4:51 am
Location: Hawaii
F=ma
F = braking force
m = mass of car
a = acceleration (in the negative direction) due to brake friction

Find a, then plug that along with the 6 seconds of braking time into Kinematics equation.

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 7:00 am 
 
User
User
User avatar

Joined: Wed Apr 22, 2009 9:21 am
F = ma
a = v/t

F = m(v/t)
F = mv/t
mv = Ft
v = Ft/m
v = (10 000)(6)/2000
v = 30

That took me about 10 minutes of hard thinking. I can't believe I passed physics 1A03. bombed the shit out of physics 1B03 though.

_________________
Image

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 7:01 am 
 
User Gold
User Gold
User avatar

Joined: Sun Jan 29, 2006 6:19 am
Location: Bay Area, California
Geologist wrote:
F = ma
a = v/t

F = m(v/t)
F = mv/t
mv = Ft
v = Ft/m
v = (10 000)(6)/2000
v = 30

That took me about 10 minutes of hard thinking. I can't believe I passed physics 1A03. bombed the shit out of physics 1B03 though.
o/

_________________
Image
I'm kind of surprised by New Mexico. I thought they'd be bluer, because that place is so fucking empty it seems like god gave up and just started copy+pasting desolate desert wasteland. -Sytar

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 7:01 am 
 
Banned
Banned
User avatar

Joined: Sun Nov 11, 2007 11:37 pm
Location: Claudeville
Thank you, Geologist.

_________________
Image

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 7:38 am 
 
User
User
User avatar

Joined: Thu Aug 07, 2008 2:33 pm
I had almost the exact same problem in my class today. Except it wasn't 10,000 N but 20,000

_________________
Light travels faster than sound. Isn't that why some people appear bright until you hear them speak? -Steven Wright

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 8:08 am 
 
User
User
User avatar

Joined: Thu Mar 16, 2006 8:29 am
Location: Oklahoma, United States
Lel, 10000/2000*6 lolol

Top
 Profile  
 Post subject:
PostPosted: Wed Feb 03, 2010 10:24 am 
 
User
User

Joined: Mon Apr 19, 2004 12:32 am
fuck I hate physics

gl

Top
 Profile  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron