Physics Homework Help?

Question

A 0.78-kg piece of wood floats in water but is found to sink in alcohol (SG=0.79), in which it has an apparent mass of 0.088 kg .

What is the SG of the wood?

Answer 1

Step 1:

The weight of the wood is .

The specific gravity of alcohol is .

The apparent weight of the wood is .

The apparent weight of the wood , where is buoyant force.

The buoyant force is .

.

The weight of the wood is .

Step 2:

Specific gravity of an object is the ratio of density of sample to density of reference substance.

The specific gravity of alcohol is .

.

The specific gravity of wood is .

.

Step 3:

Find the specific gravity of wood.

Consider .

Substitute and .

.

The specific gravity of wood is .

Solution:

The specific gravity of wood is .