# Calculating CW & CCW Torques for Point Masses on a Rod

• steveo0
In summary, the problem involves finding the cw and ccw torques, net torque, and angular acceleration of a differential horizontal rod with a length of 4 meters and a mass of 5kg, pivoted about its center. The equations used are torque = Fd and torque = (I)(alpha). Based on calculations, the net torque is -98 N/m and the angular acceleration is -14.7 m/s^2. The rod has a mass of 5kg and the weight is distributed evenly on both ends.
steveo0

## 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.

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?

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?

## 1. How do you calculate the CW and CCW torques for point masses on a rod?

To calculate the CW and CCW torques for point masses on a rod, you will need to use the formula: Torque = Force x Distance. First, determine the distance of each point mass from the pivot point. Then, multiply the distance by the force acting on each point mass. Finally, add up all the torques to get the total CW and CCW torques.

## 2. What is the difference between CW and CCW torques?

CW (clockwise) and CCW (counterclockwise) torques refer to the direction in which the torque is acting on an object. CW torque causes the object to rotate in a clockwise direction, while CCW torque causes the object to rotate in a counterclockwise direction.

## 3. Can you explain the concept of point masses on a rod?

Point masses on a rod refer to a system where multiple objects (point masses) are attached to a rod at different distances from a fixed point (pivot point). These point masses can be subjected to different forces, causing the rod to rotate around the pivot point.

## 4. How do you determine the pivot point in a system of point masses on a rod?

The pivot point in a system of point masses on a rod is the point at which the rod is fixed and does not move. This point can be determined by looking at the point where the rod is attached to a fixed object or by imagining a point where the rod would balance perfectly.

## 5. What are some real-world applications of calculating CW and CCW torques for point masses on a rod?

The concept of calculating CW and CCW torques for point masses on a rod is applicable in various fields such as engineering, physics, and mechanics. It can be used to analyze the stability of structures, determine the forces acting on a lever or pulley system, and design tools and machines that utilize rotational motion.

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