# A) An object weighs 40 g in air and has a volume of 8.0 cm3. What will be its apparent weight when immersed in water?

##### 1 Answer

#### Explanation:

To avoid confusion between grams and the acceleration due to gravity, I will assign

Weight of an object in air is

When immersed in water, the object will displace

The density of water is

Therefore the mass of the displaced water will be

The weight of the displaced water is

Therefore the object has a upward buoyant force equal to

The weight of the object in air (a downward force) and the buoyant force (an upward force) are both components of the apparent weight in water. Therefore we will have to subtract the 2 forces.

Or, using the terminology the question was asked with:

I hope this helps,

Steve