Hi im new so maybe one of you can help me understand this question, can't find it anywhere in the book.

A person weighs 723N in air and has a body-fat percentage of 29.3% .

What is the overall density of this person's body?
What is the volume of this person's body?
Find the apparent weight of this person when completely submerged in water?

So very confused

Please anyone?

Sure! I can help you understand how to approach this question.

To solve the first part, which asks for the overall density of the person's body, we need to know the formula for density:

Density = Mass / Volume

However, we are not given the mass directly. We are given the weight in newtons, which is a measure of force. To find the mass, we can use the formula:

Weight = Mass * Gravity

Gravity is a constant value, approximately equal to 9.8 m/s^2. Rearranging the formula, we can find the mass:

Mass = Weight / Gravity

Since the weight given is in newtons, we need to convert it to kilograms by dividing it by the acceleration due to gravity:

Mass (in kg) = Weight (in N) / Gravity (in m/s^2)

Now that we have the mass, we can proceed to calculate the overall density using the formula:

Overall Density = Mass / Volume

Moving on to the second part of the question, which asks for the volume of the person's body. We can rearrange the density formula:

Volume = Mass / Overall Density

For the third part, which is about finding the apparent weight of the person when completely submerged in water, we can use Archimedes' principle, which states that the buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object.

Apparent Weight = Weight in Air - Buoyant Force

To find the buoyant force, we need to know the density of water. Standard density of water is approximately 1000 kg/m^3. We can calculate the buoyant force using the formula:

Buoyant Force = Density of Water * Volume * Gravity

Substituting the values, we can find the apparent weight of the person when submerged in water.

I hope this explanation helps you understand how to approach the problem. If you need further clarification or assistance with calculations, I'm here to help!