Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Foo Off-Topic chit chat with no general subject.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 01-20-08, 10:21 PM   #1
BenLi
Hardrocker
Thread Starter
 
Join Date: Jul 2007
Bikes:
Posts: 1,569
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Physics Help Please?

A cubical block vibrates horizontally, in Simple Harmonic motion (SHM) with an amplitude of 8.0 cm and a frequency of 1.5 Hz. If a smaller block sitting on it is not to slide, what is the minimum value that the coefficient of static friction between the two blocks can be.

Answer : 0.72

Can anyone help?
BenLi is offline   Reply With Quote
Old 01-20-08, 10:35 PM   #2
EJ123
'05 NUEser
 
EJ123's Avatar
 
Join Date: Aug 2005
Bikes:
Posts: 3,370
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Message Phantomcow2. He'll know.
EJ123 is offline   Reply With Quote
Old 01-20-08, 10:37 PM   #3
stevesurf
another cat...FAB!
 
stevesurf's Avatar
 
Join Date: Jun 2005
Location: 1st star to the right...
Bikes: Merlin Ti Build, Trek Y-50, Bianchi Titanium Build, Custom Cuevas Road bike
Posts: 1,381
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
In Coulomb Damping, the frictional force each of the object's experience are opposite each other and equal. The Coefficient of static friction of the smaller object x the Normal Force (smaller object's weight) = the Frictional Force.

Find the equation that relates Force, Amplitude and Frequency of the larger object and solve for the Coeff. of Static Friction.
__________________
9
stevesurf is offline   Reply With Quote
Old 01-20-08, 10:52 PM   #4
ElJamoquio
Burning Matches.
 
ElJamoquio's Avatar
 
Join Date: Jan 2006
Location: San Jose, CA
Bikes: Motobecane Le Champion SL, Cervelo P2SL
Posts: 9,666
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
1. Figure out the acceleration with simple harmonic motion.

x = sin(wt)

Take the double derivative and find the mzximum. Hint, it should be really easy.


2. Figure out the force.

F = m*a = coefficient of friction * m
__________________
Reacting is mind candy; it requires no thought. Thinking is tedious.

Bikeforums 'Group Buy': Kinlin Rims, Sapim/DT Spokes, Formula/Bitex Hubs


"The only good race pace is suicide pace, and today looks like a good day to die."
-Steve Prefontaine
ElJamoquio is offline   Reply With Quote
Old 01-20-08, 11:25 PM   #5
BenLi
Hardrocker
Thread Starter
 
Join Date: Jul 2007
Bikes:
Posts: 1,569
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thanks for the help all. I've solved it. Here's the solution in case you were curious.

BenLi is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 03:12 AM.