Can you find the total vertical force acting on this rod?

[HappyFlower]

Homework Statement

I am trying to understand which forces are up or down and left and right. I am trying to also find out the torque that would be clockwise and counterclockwise on the figure.

Homework Equations

The Attempt at a Solution

Original Picture

Edited Picture
Arrows indicate force
CW ClockWise
CCW CountClockWise
am i even close?

 

[kuruman]

The directions of the forces are correct in the second drawing. The directions of torques (CW or CCW) are meaningless unless you specify about which point you are calculating them. What is that point?

 

[tnich]

Homework Statement

I am trying to understand which forces are up or down and left and right. I am trying to also find out the torque that would be clockwise and counterclockwise on the figure.

Homework Equations

The Attempt at a Solution

View attachment 222995
Original Picture
View attachment 222996
Edited Picture
Arrows indicate force
CW ClockWise
CCW CountClockWise
am i even close?

It looks like you are making a free body diagram for the object in the middle of the drawing. You do have the forces are pointing in the correct directions.
The torque directions are not all correct, though. How are you deciding which direction to use for a torque?

 

[HappyFlower]

The Center of Mass the little cm dot . forgot to include that.

 

[kuruman]

Then not all of them are correctly labeled. Your labeling scheme works if the torques are calculated about the left end of the rod. Can you see why?

 

[HappyFlower]

:O then i would switch them

 

[kuruman]

Switch which ones? What does your amended drawing look like?

 

[HappyFlower]

 

[kuruman]

Incorrect. Here is how to figure it out. Pretend that the rod is pivoted at the CM (or whatever origin you have chosen). Concentrate on one force and pretend it's the only force acting. Which way would the rod turn under the influence of this one force only? Label it. Repeat with the remaining forces looking at only one at a time until you have labeled them all.

 

[HappyFlower]

Ok i understand my torque now, i am having a problem with the forces. force on A would be up? force by B would be right? force by C would be down? and force by D would be left?. i just want to double check my answer.

 

[haruspex]

Ok i understand my torque now, i am having a problem with the forces. force on A would be up? force by B would be right? force by C would be down? and force by D would be left?. i just want to double check my answer.

With the exception of C, they are all a combination of a vertical force and a horizontal force. It is not useful to try to categorise each as only one of u/d/l/r. Anyway, D is clearly not left.

Why do you need to say which way each force goes in these terms? You know they are all tensions. That is enough to write down your torque equations.

 

[HappyFlower]

With the exception of C, they are all a combination of a vertical force and a horizontal force. It is not useful to try to categorise each as only one of u/d/l/r. Anyway, D is clearly not left.

Why do you need to say which way each force goes in these terms? You know they are all tensions. That is enough to write down your torque equations.

the question is asking me for total force in each direction.

 

[haruspex]

the question is asking me for total force in each direction.

If you mean vertically and horizontally, this is not a matter of categorising each force as one or the other. You need to resolve each force into its vertical and horizontal components then add up components in the same orientation.

 

[Shadow89]

Homework Statement

I am trying to understand which forces are up or down and left and right. I am trying to also find out the torque that would be clockwise and counterclockwise on the figure.

Homework Equations

The Attempt at a Solution

View attachment 222995
Original Picture
View attachment 222996
Edited Picture
Arrows indicate force
CW ClockWise
CCW CountClockWise
am i even close?

IF this is a statics problem, you have understood the basic principle. If we are talking dynamics (If the beam is not standing still), then the forces wil vary over time and you need multiple equations with multiple unknowns.

To know if the beam is standing still, you must know that the torque is equal in both directions. (Im assuming a free pivot point at CM, and that this pivot point is anchored to the wall behind it (the beam is not "falling")).

To know that the torque is equal on both sides, you must either decompose the forces into components normal on the beam; or find the distance between the acting force lines and the pivot point. Ask your professor about that last part. And while youre at it, ask him to draw less confusing beam models. This drawing is ridiculous.

Source: I study mechanical engineering at the university level. B average.

 

[kuruman]

the question is asking me for total force in each direction.

If that's all the question is asking you to find, what is the total force in any direction on an object that is at rest and remains at rest? Would you provide the full statement of the problem as was given to you?

 

[HappyFlower]

it just says total force up total force down? etc

 

[kuruman]

I would assume you are asked to find the total vertical force in the "up" direction and in the "down" direction acting on the rod. Before you consider these two separately, can you determine the sum of the "up" and "down" forces acting on the rod? Then we will figure out what they are separately.

On edit: The semi-circular contraptions on the rod look like protractors. Are the angles, as measured by the protractors, given to you? If so, what are they?