• Support PF! Buy your school textbooks, materials and every day products Here!

Potential Energy

  • Thread starter Parallel
  • Start date
42
0
1. Homework Statement

A figure is attached.
A string with length L connects two beads with masses M1,M2.
what is the equilibrium point?(in terms of the angle theta,as in the figure)

3. The Attempt at a Solution

well I know that I need to find the potential energy as a function of theta,and then find the minimum.

but I dont know how to express the potential energy in terms of theta
 

Attachments

AlephZero

Science Advisor
Homework Helper
6,953
291
You know the distance between m1 and m2 is L. To get started, find the distances of m1 and m2 from the rightangle in terms of L and theta.
 
42
0
well this is easy

for m1 : l*cos(theta)
for m2 : l*sin(theta)

I can't see how this is helping me
(by the way,this is not homework,I'm doing extra problems from the book)
 

AlephZero

Science Advisor
Homework Helper
6,953
291
The potential energy of a mass = mgh where h is the vertical distance from some point.

From those lengths, finding the vertical distance of the masses below the right angle (using alpha) is also easy.
 
42
0
can't believe I didnt see it..really easy

thanks :)
 

Related Threads for: Potential Energy

  • Last Post
Replies
8
Views
1K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
6
Views
9K
  • Last Post
Replies
8
Views
1K
Replies
2
Views
549
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
1K
Top