Which structures main function is to produce food (sugar) in a plant

Complete each of the definitions with the appropriate phrase. Precision means that measurements are close to Accuracy means that

sergiy2304 [10]

Answer: Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value

Explanation:

Precision refers to the closeness of two or more measurements to each other.

For Example: If we weigh a given substance five times and you get 5.0 kg each time. Then the measurement is very precise.

Accuracy refers to the closeness of a measured value to a standard or known value.

For Example: If the mass of a substance is 5.0 kg and one person weighed 4.9 kg and another person weighed 3.9 kg. Then, the weight measured by first person is more accurate.

Thus Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value.

5 0

3 years ago

Estimate the number of moles of water in all the Earth's oceans. Assume water covers 75% of the Earth to an average depth of 3 k

o-na [289]

Answer:

there are approximately n ≈ 10²² moles

Explanation:

Since the radius of the earth is approximately R=6378 km= 6.378*10⁶ m , then the surface S of the earth would be

S= 4*π*R²

since the water covers 75% of the Earth's surface , the surface covered by water Sw is

Sw=0.75*S

the volume for a surface Sw and a depth D= 3 km = 3000 m ( approximating the volume through a rectangular shape) is

V=Sw*D

the mass of water under a volume V , assuming a density ρ= 1000 kg/m³ is

m=ρ*V

the number of moles n of water ( molecular weight M= 18 g/mole = 1.8*10⁻² kg/mole ) for a mass m is

n = m/M

then

n = m/M = ρ*V/M = ρ*Sw*D/M = 0.75*ρ*S*D/M = 3/4*ρ*4*π*R² *D/M = 3*π*ρ*R² *D/M

n=3*π*ρ*R² *D/M

replacing values

n=3*π*ρ*R² *D/M = 3*π*1000 kg/m³*(6.378*10⁶ m)² *3000 m /(1.8*10⁻² kg/mole) = 3*π*6.378*3/1.8 * 10²⁰ = 100.18 * 10²⁰ ≈ 10²² moles

n ≈ 10²² moles

8 0

3 years ago

During our phase changes lab, where did we place the thermometer?

IrinaK [193]

The thermometer must be in contact with the ice/water only

Explanation:

In this experiment in the lab, the aim is to measure the specific latent heat of fusion of water.

The specific latent heat of fusion of a substance is the amount of heat energy required to completely melt a certain amount of the substance, mathematically:

$\lambda = \frac{Q}{m}$

where

Q is the heat supplied to the substance

m is the mass of the substance

In this experiment, the aim is to measure the specific latent heat of fusion of water. In order to do that, a mix of ice/water is heated with a certain amount of heat Q, and then it is evaluated the amount of mass m that undergoes melting.

An important precaution that must be taken in this experiment is that the temperature of the water/ice mixture remains constant and equal to the melting point of ice (otherwise, part of the heat supplied to the mixture is used to increase the temperature of the water, resulting in an inaccurate measure of Q). Therefore, a thermometer must be used to check constantly the temperature, and this thermometer must be placed inside the ice/water mixture only (It should not touch the saucepan, whose temperature can be higher).

So, the correct answer is

in contact with the ice/water only

Learn more about specific heat:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

3 0

3 years ago

Where does ATP store its energy?

RSB [31]

Answer:

D. ATP stores energy in its "tail," which is made from three phosphate groups.