Go Back   Physics Help Forum > College/University Physics Help > General Physics

General Physics General Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Aug 21st 2017, 09:46 PM   #1
Senior Member
 
Join Date: Nov 2013
Location: New Zealand
Posts: 521
D'Alembert, two blocks and an inclined plane

Ok, I am still confused about this. This time I considered all the forces and all the particles. However this is how I broke it down.

$\displaystyle F_{applied} = (\frac{m_1}{\sin \alpha}+m_2)g$

$\displaystyle F_{inertial} = (m_2 +\frac{m_1}{\sin \alpha})\ddot{s} $

However the solution misses out the sin(alpha) in the applied force. Are constraints always ignored when writing down applied forces?
Attached Thumbnails
D'Alembert, two blocks and an inclined plane-d-alembert-2.08-problem.png   D'Alembert, two blocks and an inclined plane-d-alembert-2.08-solution.png  
kiwiheretic is offline   Reply With Quote
Old Aug 22nd 2017, 10:10 AM   #2
Physics Team
 
ChipB's Avatar
 
Join Date: Jun 2010
Location: Naperville, IL USA
Posts: 2,271
The F_applied is $\displaystyle m_1 g \sin \alpha - m_2 g$. You have m_1 divided by sin alpha rather than multiplied by sin alpha. And for F_inertial it's simply $\displaystyle \sum m a = (m_1 + m_2) a$.
ChipB is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > General Physics

Tags
blocks, dalembert, inclined, plane



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Inclined Plane alagarn Energy and Work 1 Mar 26th 2012 12:07 PM
Inclined Plane Problem subho Kinematics and Dynamics 3 Sep 2nd 2010 01:17 AM
question to do with inclined plane cooltowns Kinematics and Dynamics 6 May 27th 2009 09:10 PM
Car on an inclined plane ignus275 Kinematics and Dynamics 7 Mar 22nd 2009 09:01 AM
Inclined plane werehk Kinematics and Dynamics 2 Aug 17th 2008 06:24 PM


Facebook Twitter Google+ RSS Feed