#1

So, I need help with this physics project im doing, and I thought that the lovely (and very lively) community at UG might be able to help... It's due tomorrow, and I'm drawing a blank.

We have to balance a load of weight on a flatbed trailer.

I figure since F=mg, I can calculate the F of the weight on the axle / tongue of the flated...

And T=Fd (T=torque), so I can caluclate the torque or Force on the axle...

But then I get lost. Using numbers around 22,000 lbs and 18,000 lbs (large machinery) I'm getting something like 600,000 N of force.

Help? (600,000 N of force is about 134831.5 lbs, or 67 TONS)

We have to balance a load of weight on a flatbed trailer.

I figure since F=mg, I can calculate the F of the weight on the axle / tongue of the flated...

And T=Fd (T=torque), so I can caluclate the torque or Force on the axle...

But then I get lost. Using numbers around 22,000 lbs and 18,000 lbs (large machinery) I'm getting something like 600,000 N of force.

Help? (600,000 N of force is about 134831.5 lbs, or 67 TONS)

#2

weight is a force, so the pounds you are putting on the trailer are already a force. the english unit for mass is slug (typically just referred to as lb mass).

#3

I dont know if you can use lbs as your units, try using the metric equivalent

#4

What?

How about you start with the question. Then give the numbers. Then tell us what you're having issues with.

Right now I have no clue what the **** you're trying to figure out.

How about you start with the question. Then give the numbers. Then tell us what you're having issues with.

Right now I have no clue what the **** you're trying to figure out.

#5

ok, so if you convert pounds into kg (divide by 2.2), then go F = mg, you get two forces, F1 and F2. Then T = F1d1 = F2d2. Then you can assign an arbitrary value for d1, and solve for d2. d1 is the distance to the right of the fulcrum, and d2 is the distance to the left of the fulcrum.

#6

what exactly are you trying to achieve?

#7

Look up center of gravity formulas, Then look up torque formulas.

Then write out the entire damn problem instead of giving us little bits and pieces that don't tell us anything.

Maybe that will help.

Then write out the entire damn problem instead of giving us little bits and pieces that don't tell us anything.

Maybe that will help.

#8

You're getting 600 000 N of force for

*what*? What are you trying to work out here?
#9

Assuming you are looking at a side view of the tailer, use the axle as your origin (center) point. All vertical forces should equal zero, not F=ma. F=ma is used for dynamics problems. I'm assuming this is a static equilibrium problem?

So one force would be the weight of the object, or Weight = mass*gravity, and the other balancing force would be the tongue weight. Sum up moments about the center point. You can then solve for the moment arm distance from the center point. This will give you the location of where to put the object with respect to the center point.

So one force would be the weight of the object, or Weight = mass*gravity, and the other balancing force would be the tongue weight. Sum up moments about the center point. You can then solve for the moment arm distance from the center point. This will give you the location of where to put the object with respect to the center point.

*Last edited by fsae0607 at Feb 23, 2009,*

#10

We need more info on this problem, because now my head is working on more aspects of it.

#11

6 million is the answer.

#12

Ask Einstein... Oh wait...

Yeah nevermind.

Yeah nevermind.

#13

6 million is the answer.

haha nailed it!

#14

I'm sorry, I should have been more specific, thanks for all the help so far!

What the actual project is... is balancing our assigned weight so that the tires have an equal and street legal weight distribution...

We have a 25,000 lb (roughly) Trackhoe and a 18,500 lb (roughly) Wheel loader.

Our Flatbed weighs 7,000 lbs (roughly) and is 48 ft by 92 inches, we have 5 axels on the flatbed...

V V

----________________

XX 00 000

I'm not asking for a solution, more like a guide as to how to do it, thanks again!

What the actual project is... is balancing our assigned weight so that the tires have an equal and street legal weight distribution...

We have a 25,000 lb (roughly) Trackhoe and a 18,500 lb (roughly) Wheel loader.

Our Flatbed weighs 7,000 lbs (roughly) and is 48 ft by 92 inches, we have 5 axels on the flatbed...

V V

----________________

XX 00 000

I'm not asking for a solution, more like a guide as to how to do it, thanks again!

#15

#16

It's due soon and i dont have time to make a new thread, i apologize i didnt know that there was a math thread

#17

42

#18

Lbs isn't an SI unit.

#19

Lbs isn't an SI unit.

Winner, although it was said earlier.

SI units only work if you work only in SI units. Try using kg.