# Buoyancy lab for my physics class

1. Dec 3, 2003

### Skipperchrldr

I'm trying to do a lab for my physics class. It wants me to calculate the weight of the water displaced when I put a 500-g mass in a cup of water. I know the volume wich is 59.0 ml. And I also know that the Buoyant force i s 0.56 N. I thought that the Buoyant force equals the volume of the water displaced but my friend told me that I have to convert the volume (59.0 ml) to Newtons. I was wondering which one of us was right and if my friend was right i was wondering how to convert ml to Newtons.

2. Dec 3, 2003

### chroot

Staff Emeritus
You cannot convert units of volume (mL) to units of force (newtons). They are two entirely different kinds of units.

What do you mean "I know the volume wich is 59.0 ml?" Do you mean the volume of the mass is 59 mL, or the volume of the cup of 59 mL, or what?

- Warren

3. Dec 3, 2003

### Skipperchrldr

The volume of the water displaced by the 500-g mass is 59.0 ml

4. Dec 3, 2003

### HallsofIvy

If a 59.0 ml. object (of any density greater than that of water) is dropped into water, then it displaces 59.0 ml of water (of course!).

The weight of that water is 59.0 ml * density of water in kg. per ml times 9.8 m/s2 Newtons.

5. Dec 4, 2003

### Skipperchrldr

Thanks SO much guys. That helped SOOOO much!!!

Last edited: Dec 11, 2003