Work on an object

1. Jun 22, 2008

student 1

1. The problem statement, all variables and given/known data
Object one pushes on object 2 as the objects move together, like a bulldozer pushing a stone. Assume object 1 does 15 J of work on object 2. Does Object 2 do work of object 1? If possible determine how much work?

2. Relevant equations

3. The attempt at a solution
I was thinking it would do work on object 1, could someone just point me in the right direction on how to start this. I'm not real sure where to begin. I was thinking it might be negative work that the 2nd object does on number 1.?????

2. Jun 22, 2008

rock.freak667

What is needed for an object to do work?

3. Jun 22, 2008

student 1

Force and distance moved?

4. Jun 23, 2008

rock.freak667

What is the force that object 2 exerts on object 1?

5. Jun 23, 2008

ajhunte

I am pretty sure that the answer is 15J.

Lets try it with numbers (although they don't really matter.) Lets say the bulldozer applies 5 Newtons for 3 Meters (3*5=15). This means that if the rock was not present, it would take 15 Joules less to move those 3 Meters. You can think of this -15J as the work that the boulder does on the bulldoser. It is the extra energy that the bulldozer has to do for those 3 meters (or any distance for what it matters).

6. Jun 23, 2008

rock.freak667

Basically it was just to apply Newton's third law.

7. Jun 23, 2008

student 1

Thanks a bunch!!!