# Can you figure this one out?

1. Dec 13, 2005

### 9000_red

let's say a 180 lbs person needs to move a 2000 lbs object 50 feet. that would take 100,000 ft/lbs. how do you apply that in terms of how much effort it would take from a 180lbs man? divide by 180 and get 555.5? how do you determine the amount of force required to get this object rolling? this doesn't have to be exact, so friction etc doesn't have to be taken into account for my purposes....

2. Dec 13, 2005

### HallsofIvy

Staff Emeritus
I don't see how the person's weight has anything to do with it.
Looks to me like you have learned some formulas, but no concepts!

Moving a 2000 lb. object 50 feet horizontally would not require 100000 ft-lbs of work. Ignoring friction, it would require no work at all. Moving it 50 feet vertically upward would require 100000 ft-lbs of work because it would have acquired 100000 ft-lbs of potential energy.

3. Dec 13, 2005

### 9000_red

i'm trying to figure out how much effort it takes for a man to pull a pallet of cokes (2000lbs) from one point in a grocery store to another (50ft). if the pallet is moved by a jack with polyurethane wheels across smooth concrete, or tile floors like in wal-mart, the friction coefficient would be

Hardrubber on Concrete f = 0,01 -0,02m

but i'm no math whiz, honestly i suck at most of it.... but what's the simplest way to say it would take a guy _ lbs of effort to get this pallet rolling....

4. Dec 13, 2005

### 9000_red

bump 4 help

5. Dec 14, 2005

### Tide

HINT: Calculate how much work is done by the force of friction.

6. Dec 14, 2005

### HallsofIvy

Staff Emeritus
As I said before, if you are moving something horzontally and ignore friction, there will be no work done at all. All the work in this problem depends on the friction.