Solve Angular Velocity when Initial Theta=30º, Bar Mass=m, AB=L/2, BC=L/2

  • Thread starter Mr. Leal
  • Start date
In summary, the conversation discusses a homework problem where the initial angle and mass are given, and the goal is to find the angular velocity at a specific angle. The solution involves using conservation of energy and the relationship V=w*L/2 to determine the angular velocity. The importance of showing one's own attempt in posting homework problems is also emphasized.
  • #1
Mr. Leal
2
0

Homework Statement


the problem gave a initial θ=30º, bar mass=m
they want to know the angular velocity when θ=0º
AB=L/2 and BC=L/2

attachment.php?attachmentid=48747&stc=1&d=1340989659.jpg
My attempt:
rest in the inicial state, so: v=0, w=0 and T1=0
using conservation of energy and V=w*L/2
I can find w( angular velocity)
bit I'm not quite sure that this is the right metod

thanks
 

Attachments

  • PTDC0397.JPG
    PTDC0397.JPG
    11.9 KB · Views: 673
Last edited:
Physics news on Phys.org
  • #2
read the rules about how to post homework problems. You have to show some attempt yourself.
 
  • #3
phinds said:
read the rules about how to post homework problems. You have to show some attempt yourself.

sorry, i reposted it
 
  • #4
I don't know what your w, V, v and T1 are but your basic idea is correct.
 
  • #5
for your question!

Your approach using conservation of energy and the relationship V=w*L/2 is correct. To solve for angular velocity, you can use the equation T1+U1=T2+U2, where T is kinetic energy and U is potential energy. In the initial state, T1=0 and U1=mgh, where h is the height of the center of mass of the bar. In the final state, T2=1/2*I*w^2, where I is the moment of inertia of the bar and U2=0. By setting T1+U1=T2+U2 and substituting in the given values, you can solve for w. This method is valid because the problem does not involve any external forces or non-conservative forces.
 

1. What is angular velocity?

Angular velocity is a measure of the rate at which an object rotates or moves around a central point, and is usually measured in radians per second.

2. How do you calculate angular velocity?

The formula for angular velocity is ω = Δθ/Δt, where ω represents angular velocity, Δθ represents the change in angle over a period of time, and Δt represents the change in time.

3. What does initial theta refer to in this problem?

In this problem, initial theta refers to the starting angle of the rotating object, which is given as 30 degrees.

4. How does the bar mass and length affect the angular velocity?

The bar mass and length do not directly affect the angular velocity, but they can indirectly affect it by changing the moment of inertia of the rotating object.

5. Can you provide an example of using this formula to solve for angular velocity?

Sure, for example, if a bar with a mass of 2 kg and a length of 0.5 meters is rotated from an initial angle of 30 degrees to a final angle of 60 degrees in 2 seconds, the angular velocity would be ω = (60-30)/(2-0) = 15 degrees per second.

Similar threads

  • Introductory Physics Homework Help
Replies
10
Views
803
  • Engineering and Comp Sci Homework Help
Replies
5
Views
3K
Replies
3
Views
777
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
Replies
5
Views
677
  • Introductory Physics Homework Help
Replies
12
Views
808
Replies
15
Views
864
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
914
Replies
13
Views
791
Back
Top