Help Union Labor at Convention Center

[yvonnes]

Help! Union Labor at Convention Center

I was hoping someone could help me figure out the following: If I have a 40 lb trough filled with 250- 12oz sodas and 40 lbs of ice on top of a sico table on wheels that weighs 125lbs...how can i figure out if a union employee can push this to our events. Right now they are only allowed to lift no more than 50 pounds. What in weight are they pusing? How can I figure that out? Please help!

 

[Dr Lots-o'watts]

It depends on many things. If they are big wheels, and you roll on a very flat floor, it could be ok, but if the wheels are small and the rolling surface is rough and not level, this could be quite a job.

Why can't 2-3 people push or pull together?

 

[yvonnes]

It depends on many things. If they are big wheels, and you roll on a very flat floor, it could be ok, but if the wheels are small and the rolling surface is rough and not level, this could be quite a job.

Why can't 2-3 people push or pull together?

We have very large events that require us to push many tables at a time. I need a formula that I can use to show to the union. The wheels are about 5 inches from the ground and our floors are flat and smooth...hospital like.

 

[russ_watters]

You can start with the friction equation which is friction coefficient times weight = force. But estimating the coefficient will be difficult. For very good wheels with bearings, it might be .1, but for mediocre wheels it could be .3. For .1 and a weight of 400lb, that gives 40lb of force. But it could easily be double or triple that if the wheels are bad.

 

[JaWiB]

Simple answer: they aren't lifting anything; they're pushing!

I think you'll have to go out and get a scale of some sort and gather some empirical data :D

 

[Dr Lots-o'watts]

Try this:

1. Get a volunteer to push a regular person-scale against the table.
2. Take the reading as soon as the table starts moving.

In principle, the hardest part is to get it going from a standing start. So the force never has to be be greater than that reading as it starts moving.

Of course, nothing prevents anyone to push as hard they want. And don't forget that when it's going, it might be as hard to stop.

 

[JDługosz]

I agree, the physics answer is that arbitrary little force is needed. The real interesting part involves friction and lumps in the carpet and so on, which were not stated with the problem.