Calculating CW & CCW Torques for Point Masses on a Rod

Click For Summary
SUMMARY

This discussion focuses on calculating clockwise (cw) and counterclockwise (ccw) torques for point masses on a horizontal rod. The scenario involves a massless rod of 6 meters with 2kg point masses at each end, pivoted at the center, where the torque is calculated using the formula torque = Fd. The participants clarify that in equilibrium, the sum of torques equals zero, and they explore the implications of adding mass to the rod itself, leading to further calculations of angular acceleration using the moment of inertia.

PREREQUISITES
  • Understanding of torque calculations using the formula torque = Fd
  • Knowledge of moment of inertia concepts
  • Familiarity with angular acceleration and its relationship to torque
  • Basic principles of equilibrium in physics
NEXT STEPS
  • Study the concept of moment of inertia for different shapes, particularly rods
  • Learn about the equilibrium conditions for systems involving torques
  • Explore angular acceleration calculations in rotational dynamics
  • Investigate the effects of adding mass to a pivoted system on torque and acceleration
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone studying mechanics, particularly those focusing on rotational dynamics and torque calculations.

steveo0
Messages
3
Reaction score
0

Homework Statement


Find all cw and ccw torques. I don't know how to post the picture, but I was absent from my physics class today for AMC so I missed out. First problem: A horizontal massless rod of length 6 meters is pivoted about its center. There is a 2kg point mass on each end of the rod.


Homework Equations


torque = Fd


The Attempt at a Solution


So I looked at the textbook, but they only provide examples with cylinders. So I just need one example for this and I think I can pretty much do the rest. Do I calculate the Force for each one? or do I use the moment of Inertia?
 
Physics news on Phys.org
Welcome to PF.

You mean it's a see-saw.

If it is in equilibrium then the sum of the Torques are 0.

The F*2m on one side is equal to the F*2m on the other.
 
oh. thanks. lol that's that only example where they're both equal. so uh.

1. Homework Statement
Find all cw and ccw torques. Find the net torque. Find the angular acceleration. A differential horizontal rod has a length of 4 meters and a mass of 5kg. It is pivoted about its center. 2. Homework Equations
torque = Fd
torque = (I)(alpha)3. The Attempt at a Solution
I found Fg = -49 N
torque = Fxd = -98 N/m
angular acceleration = torque / moment of inertia = -98 / (20/3) = -14.7 m/s^2?
is this right?
 
Does the rod have mass?
 
yeah 5kg
 
If it is pivoted about the center where is the net force?

Is there a weight on one end as well?
 

Similar threads

Minimum angular velocity of a point mass on a rotating rod
  • · Replies 5 ·
Replies
5
Views
863
Does distance affect torque in hanging sign problem?
  • · Replies 42 ·
2
Replies
42
Views
4K
Calculating Torque on this Square
  • · Replies 20 ·
Replies
20
Views
3K
Finding the mass of a ball and a rod using torque
  • · Replies 8 ·
Replies
8
Views
2K
Stress on a spaghetti rod balanced from its middle
  • · Replies 6 ·
Replies
6
Views
1K
Finding mass of unbalanced meter stick from torque
  • · Replies 2 ·
Replies
2
Views
2K
Rod w/ Pivot and Attached Mass Pendulum
  • · Replies 4 ·
Replies
4
Views
2K
Uniform rotating rod about a point at one end of the rod
  • · Replies 3 ·
Replies
3
Views
2K
How is net torque zero about hinge of rod in ball rod system
  • · Replies 7 ·
Replies
7
Views
3K
Find velocities when a mass leaves a system of a rod with two masses
  • · Replies 10 ·
Replies
10
Views
2K