Which of the following is an example of an action done to maintain homeostasis?

the position-time graph shows the motion of four people. label the lines on graph need on the motion description in this table.

sertanlavr [38]

Line 1: straight horizontal line
Line 2: straight line at a slope
Line 3: exponential growth curve
Line 4: the topmost curve (the one that initially increases but then starts levels out)

3 0

3 years ago

Photosynthesis by land plants leads to the fixation each year of about 1 kg of carbon on the average for each square meter of an

Rama09 [41]

Answer:

a) mass of carbon directly above 1 ( each) square meter of the earth is 1.65kg

b) all CO₂ will definitely be used up from the atmosphere directly above a forest in 1.65 years

Explanation:

first we calculate the moles of carbon

moles = mass/molar mass

= 1kg/12gmol⁻¹

= 1000g/12gmol⁻¹

= 83.33 mol

now using the ideal gas equation

we find the volume of co₂required based on 83.33 moles

PVco₂ = nRT

Vco₂ = nRT/P

Vco₂ = (83.22mol × 0.0821L atm k⁻¹ mol⁻¹ 298 K) / 1 atm

Vco₂ = 2083.73 L

so since CO₂ in air is 0.0390% by volume in the atmosphere, we find the the total amount of air required to obtain 1kg carbon

therefore

Vair × 0.0390/100 = 2038.73L

Vair = (2038.73L × 100) / 0.0390

Vair = 5.23 × 10⁶L

therefore 5.23 × 10⁶ L of air will be required to obtain 1kg carbon

a)

Here we calculate the mass of air over 1 square meter of surface.

Remember that atmospheric pressure is the consequence of the force exerted by all the air above the surface; 1 bar is equivalent to 1.020×10⁴kgm⁻²

NOW

mass of air = 1.020×10⁴kgm⁻² × 1m²

= 1.020×10⁴kg

= 1.020×10⁷g [1kg = 10³g]

we now find the moles of air associated with it

moles = mass/molar mass

= 1.020 × 10⁷g / ( 20%×Mo₂ + 80%×Mn₂)

= 1.020 × 10⁷g / ( 20%×32gmol⁻¹ + 80%×28gmol⁻¹)

= 1.020 × 10⁷g / 28.8 gmol⁻¹

= 354166.67mol

so based on the question, for each mole (air), there is 0.0390% of CO₂

now to calculate the moles of CO₂ we say;

MolesCo₂ = 0.0390/100 × 354166.67mol

= 138.125 moles

Now we calculate mass of CO₂ from the above findings

Moles = mass/molar mass

mass = moles × molar mass

= 138.125 moles × 12gmol⁻¹

= 1657.5g

we covert to KG

= 1657.5g / 1000

mass = 1.65kg

therfore mass of carbon directly above 1 ( each) square meter of the earth is 1.65kg

b)

to find the number years required to use up all the CO₂, WE SAY

Number of years = total carbon per m² of the forest / carbon used up per m² from the forest per year

Number of years = 1.65kgm⁻² / 1kg²year⁻¹

Number of years = 1.65 years

Therefore all CO₂ will definitely be used up from the atmosphere directly above a forest in 1.65 years

6 0

3 years ago

Which of the following is a mixture of substances?

Stels [109]

Answer:

the answer is c

b/c contain more than one element

7 0

3 years ago

Which two changes would increase the gravitational force between two

scoundrel [369]

Answer:

B. Increase the mass of one of the objects.

E. Decrease the distance between the objects.

Explanation:

To effect an increase in the gravitational force between two objects, the mass of both objects should be increased and the distance between them reduced.

This is derived from the Newton's law of universal gravitation:

It states that "the force of gravity between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them".

Therefore, if the mass of the two bodies are increased and the distance between them reduced, the gravitational force of attraction will increase.

4 0

3 years ago

Help me is a critic acid a solid or a liquid??

Musya8 [376]

Answer:

See below

Explanation:

It is neither, at least not at room temperature.

Citric acid exists as a power at room temperature, but can be crystallized from cold water. This can be considered it's " solid state, " but as I mentioned before this acid is a powder. Take a look at the attachment below. This is a citric acid present as a crystal;

7 0

3 years ago