# Two boxes dragged, find force

1. Feb 17, 2010

### PinguNinjitsu

1. The problem statement, all variables and given/known data
Two 103 kg boxes are dragged along a fric-
tionless surface with a constant acceleration
of 1.19 m/s2, as shown in the figure.
Each rope has a mass of 1.03 kg.

2. Relevant equations
F=ma

3. The attempt at a solution
I wasn't sure where to go with this problem. I am mostly just wondering if the weight of the rope matters at all. I don't think I have ever come across a problem where the rope had a weight. Also just to make sure I'm thinking this through the right way, if the weight of the rope doesn't matter I would just act as the masses as one and then from the force from there? I'm not sure if that is right, I haven't been in a Physics class in 2 or 3 years so I'm a little rusty. Any help would be great! Thanks

2. Feb 17, 2010

### HallsofIvy

Well, if you are accelerating the rope along with the boxes, yes, its mass will matter (not weight, mass because this is horizontal motion and gravity doesn't enter into it). Just add all masses, both boxes and ropes, together and multiply by the acceleration: F= ma.

3. Feb 17, 2010

### Svensken

Hello.

Try to think of the boxes as one. Combine the masses since there is no friction.
Think of it as one mass.

4. Feb 17, 2010

### Svensken

WOW! that reply came just as i wrote mine. haha

5. Feb 17, 2010

### PinguNinjitsu

Thank you! Thats what I was thinking I was supposed to do, just wanted to make sure!