Give an example of a physical model of the circulatory system

PLZ HELP Question 14 of 25 What is the name for a representation of the physical world?

JulijaS [17]

Answer:

Model

Explanation:

A model of anything is something you make to represent it in it's physical world form

8 0

3 years ago

A rectangular block of solid carbon (graphite) floats at the interface of two immiscible liquids.

Sergio039 [100]

Explanation:

Let us take the volume of block is x.

Since, the block is floating this means that it is in equilibrium. Formula to calculate net force will be as follows.

$F_{net} = Buoyancy force(F_{b}) - weight force(w)$

Also, buoyancy force $(F_{b})$ = (volume submerged in water × density of water) + (volume in oil × density of oil)

$(F_{b})$ = $(0.592 V \times \rho) + (1 - 0.592)V \times 1000 g$

= $(0.592 V \times \rho + 408 V)$ g

As, W = V × density of graphite × g

It is given that density of graphite is $2.16 g/cm^{3}$ or 2160 $kg/m^{3}$ .

So, W = 2160 V g

$F_{net}$ = (0.592 V \rho + 408 V) g - 2160 V g = 0

$0.592 \rho$ = 1752

$\rho$ = 2959.46 $kg/m^{3}$ or 2.959 $g/cm^{3}$ is the density of oil.

It is given that mass of flask is 124.8 g.

Mass of 35.3 $cm^{3}$ oil = $35.3 \times 2.959$ 104.7 g

Hence, in second weighing total mass will be calculated as follows.

(124.8 + 104.7) g

= 229.27 g

Thus, we can conclude that in the second weighing mass is 229.27 g.

5 0

3 years ago

What are the reasons global warming is caused my humans and animals. Plz help 100 points

pantera1 [17]

Global Warming has been increased by living organisms like animals and humans by many ways:

1) We burn fossil fuels, which is very bad for our Environment's health
2) Animals like cows & buffalo produces a lot of methane which causes Global Warming.
3) Animals cut a lot of trees for their products, so increase the amount of Carbon dioxide in the atmosphere, thus increases Global Warming.
4) We don't minimize our dependence on Non-renewable source of energy which 'causes a lot of pollution in the environment

Hope this helps!

8 0

3 years ago

Read 2 more answers

Ca(OH)2 (s) precipitates when a 1.0 g sample of CaC2(s) is added to 1.0 L of distilled water at room temperature. If a 0.064 g s

Nina [5.8K]

Answer:

D) Ca(OH)₂ will not precipitate because Q < Ksp

Explanation:

Here we have first a chemical reaction in which Ca(OH)₂ is produced:

CaC₂(s) + H₂O ⇒ Ca(OH)₂ + C₂H₂

Ca(OH)₂ is slightly soluble, and depending on its concentration it may precipitate out of solution.

The solubility product constant for Ca(OH)₂ is:

Ca(OH)₂(s) ⇆ Ca²⁺(aq) + 2OH⁻(aq)

Ksp = [Ca²⁺][OH⁻]²

and the reaction quotient Q:

Q = [Ca²⁺][OH⁻]²

So by comparing Q with Ksp we will be able to determine if a precipitate will form.

From the stoichiometry of the reaction we know the number of moles of hydroxide produced, and since the volume is 1 L the molarity will also be known.

mol Ca(OH)₂ = mol CaC₂( reacted = 0.064 g / 64 g/mol = 0.001 mol Ca(OH)₂

the concentration of ions will be:

[Ca²⁺ ] = 0.001 mol / L 0.001 M

[OH⁻] = 2 x 0.001 M = 0.002 M ( From the coefficient 2 in the equilibrium)

Now we can calculate the reaction quotient.

Q= [Ca²⁺][OH⁻]² = 0.001 x (0.002)² = 4.0 x 10⁻⁹

Q < Ksp since 4.0 x 10⁻⁹ < 8.0 x 10⁻⁸

Therefore no precipitate will form.

The answer that matches is option D

8 0

3 years ago

how did the boiling point of plain water compare to that of water with salt? Compared to water with sugar?

elixir [45]

The boiling point of plain water is less than the boiling point of both salt and sugar water.

<h3>What is boiling point?</h3>

Boiling point can be defined as the point when the pressure exerted by the surroundings upon a liquid is equal to the pressure exerted by the vapour of the liquid.

The boiling point of plain water is 100°C which increases upon addition of solute substances such as salt and sugar.

But salts are usually made up of ionic bonds while sugar are made up of covalent bonds. This means that more energy would be required to boil salt solution due to its ionic bonds.

Therefore, the boiling point of salt water is highest following sugar water before plain water which is the lowest.

Learn more boiling point here:

brainly.com/question/14008526

#SPJ1

7 0

2 years ago