How Do You Calculate Apparent Weight and Buoyant Force?

[ChunkymonkeyI]

Homework Statement

1) A 0.0200 kg metal(density=4.000 g/cm^3) object is suspended from a thead and is submerged in a jar of oil(density=1.500 kg/dm^3) What is the apparent weight in the thread) For this one I keep doing this one but I think I am getting it wrong because of my conversion

2)A metal cylinder has a voluem of 2150 mm^3. Find the buoyant force when it is completely submerged in a liquid that has a density of 0.900 kg/dm^3 For this one Idk y my answer is wrong but can someone explain 2 me because I think this one I'm getting wrong because of my units but please show me the steps on how 2 solve this problem

Homework Equations

The Attempt at a Solution

1)(1500 kg/m^3)(40 kg/m^3)(9.80 m/s^2)

2)(800 kg/m^3)(2.150 m^3)(9.80 m/s^2)

 

[rude man]

First, 4g/cm^3 does not equal 40 kg/m^3.

Second, you need the denssity of your oil.

Third, read about that old Greek, Archimedes.