# Homework Help: Tention and Density

1. Sep 25, 2011

### Wroxley

I stumbled upon this question and I have no idea how to figure it out:

A ball bearings mass is 180g, it is on some string with oil that has a density of 800Kg M^-3
Calculate the tention of the string if the ball bearing had a density of 8000kg m^-3

Density= Mass/Volume

Tention = Force/Area?

Balls Volume = 0.18 Kg * 8000kg m^-3 = 1440m^3?

2. Sep 25, 2011

### SteamKing

Staff Emeritus
Tension (not tention) is the force which tends to keep the string taut. If the ball bearing is tied to the string before it is put into the oil, what is the tension in the string? How does this tension change after the ball bearing is immersed in the oil?

3. Sep 25, 2011

### Redbelly98

Staff Emeritus
Welcome to Physics Forums.

Actually, tension = force (of a string or rope)

When you do the calculation you are showing above, the resulting units are kg2 m-3, which is not a volume.

Try using the equation you wrote earlier,
Density= Mass/Volume​
so
Volume = ?​

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