# Overhanging beam

1. Feb 20, 2017

### Ozkan Suna

The question is:

How do I find all the reactions? I haven't worked with a similar problem before, so I'm kinda confused. Hope someone will help!

Thanks from now.

2. Feb 20, 2017

### Staff: Mentor

Finding all forces should be easy from the sketch. To calculate their values: Both net force overall and torque around a point of your choice have to be zero in equilibrium.

3. Feb 20, 2017

### Ozkan Suna

'' Point of my choice has to be zero '' Does it mean I have to add a charnier? Sorry for the confusion

4. Feb 20, 2017

### Staff: Mentor

You don't have to add anything. Pick a random point. Calculate all torques around that point from all the forces. The sum has to be zero.

5. Feb 23, 2017

### Ozkan Suna

So if I want the moment ΣMz = 0; Dy * 6a - P*10a - p*5a*2,5a = 0
and then isolate Dy and substitute it in ΣFy = 0; By + Dy = 5ap + P??

6. Feb 23, 2017

### Staff: Mentor

If you introduce new variables, you should define them somewhere. An explanation what is what would be useful as well.
Why 10a?
","? And assuming you mean 2.5, why 2.5?
Sure.

7. Feb 23, 2017

### Ozkan Suna

1) We have a single force at the end of the beam. So I say the force multiplied with the total lenght.

2) From the left side of the beam to the half we have distributed load. So I want to find where the single force attacks, and that is on the half on the beam, right?

8. Feb 23, 2017

### Staff: Mentor

What is the middle between "2a to the left" and "3a to the right"?

9. Feb 25, 2017

### Ozkan Suna

Oh, so we have to split it up to 2a/2 = a and 3a/2 = 1.5a?

10. Feb 25, 2017

### Staff: Mentor

You can split it in two pieces, but simply finding the middle works as well. The middle is not 2.5 a to the right of the support.

11. Feb 26, 2017

### Ozkan Suna

1.5 a right?

12. Feb 26, 2017

### Staff: Mentor

No.

Draw it on a piece of paper if that helps. Or use signs: Where is the middle between -2 and +3?

13. Feb 26, 2017

### Ozkan Suna

a?

14. Feb 26, 2017

### Staff: Mentor

Stop guessing please. How do you calculate the average between two values?

15. Feb 26, 2017

### Ozkan Suna

Not guessing, it's confusion.
The average of -2 and 3 is: -2 + 3 / 2 = 1/2

16. Feb 26, 2017

Right.