Recent content by derail

I am trying the method and equation at http://www.efunda.com/formulae/solid_mechanics/columns/calc_column_critical_load.cfm How do I calculate the Young's Modulus? This requires stress which requires force. What force would be used?

I am not designing columns from scratch, these columns are actually I beams. I am just trying to prove that they are strong enough to hold the weight of the beam and roof. So I am trying to find the force they can hold. I thought I could do this with the safety factor. How does the fact that...

How does the situation change when there are two columns instead of just one? Should I try and see if the columns will hold up outside of the buckling situation?

That looks very helpful but I am not sure, that website incorporates column buckling which I wasn't going to include as a factor. Then again, column buckling could be a major factor in this situation. What is really hinges on then is, would it be possible for a column to not be strong enough...

Beam held up by two columns I apologize in advance if you think this should really go in the homework help area, I am not sure because this isn't a homework problem, but rather my struggle to understand and carry out concepts. If it needs to be re-posted, or moved, I understand. :) In a...

So my thought process was, we can take the flow rate equation and incorporate the concentration of salt to water?

I am trying to find a differential equation for the amount A(s), meaning the amount of salt. I miss wrote that last equation, you are right. However, I am trying to get the amount of salt, so I figure if I know the amount of water then I can use the concentration to get the amount of salt? like...

So the water flow rate =(-2*t)+400, and we know that 3 pounds/gallon is being pumped in so we should be able to write: =((-2*t)+400)*3 to correct the units for Pounds per minute?

Decreasing my bad, so we actually get -2*t+400, now to write that equation.

So after t mins we should have, 2*t+400 gallons of water.

So the rate of change is 2g/m flowing out. The tank started with 400 gallons.

I see, we should be able to use the same logic to make is so that the units of the A(t) are lbs per minute by using the concentration of salt water. Do you have a suggestion on how to write the equation? I figure the way we are doing this, we are basically adding two separate equations, one...

I am not sure how to incorporate the flows of the liquid into the equation when I am ultimately looking for an equation for the amount of salt.

So wouldn't the 8 gallons/min be the flow rate? I would think i can find the rate of salt flowing out by taking the 6 gallons/min and the 3 pounds/gallon and trying to get pounds/minute by multiplying them to get 18 pounds/minute.

Homework Statement Suppose that a large mixing tank initially holds 400 gallons of water in which 65 pounds of salt have been dissolved. Another brine solution is pumped into the tank at a rate of 6 gal/min, and when the solution is well stirred, it is pumped out at a faster rate of 8 gal/min...