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3 years ago

Insulating materials are rated by their _____. specific heat heat index r-value temperature resistance

Physics

2 answers:

jeka57 [31]3 years ago

4 0

Answer: Option (c) is the correct answer.

Explanation:

The difference in temperature when per unit of heat flux is required by one unit of heat flux between a barrier of warmer and colder surface present in steady state condition is known as R-value.

Mathematically, R-value = $\frac{\text{Temperature difference}\times \text{Area}\times \text{Time}}{Heat loss}$

Thermal resistance of insulating products or materials can be known with the help of R-value. As more is the r-value of a substance more will be its insulating power.

Therefore, we can conclude that insulating materials are rated by their r-value.

Leokris [45]3 years ago

3 0

That would be the R-value

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There are two different alleles for the number of fingers on the hands: 5 finger allele and 6 finger allele. When both the 5 fin

padilas [110]

Answer:

The 6 fingers allele is dominant

Explanation:

We are told that the the individual is genotypically heterozygous, that is the have both types of the finger allele: the 5 finger allele and the 6 fingers allele however phenotypically, 6 fingers are observed. From this we can conclude that the 6 fingers allele is the one that is dominant because it is the one that is expressed phenotypically.

8 0

2 years ago

17. A volleyball weighs about 300 grams.

atroni [7]

Answer:

PE = 44.1 J

Explanation:

Ok, to have the specific data, the first thing we must do is convert from grams to kilograms. Since mass must always be in kilograms (kg)

We have:

1 kilograms = 1000 grams.

We convert it using a rule of 3, replacing, simplifying units and solving:

$\boxed{\bold{x=\frac{gr*1\ kg}{1000\ gr}=\frac{300\ gr*1\ kg}{1000\ gr}=\frac{300\ kg}{1000}=\boxed{\bold{0.3\ kg}}}}$

==================================================================

Earth's gravity is known to be 9.8 m/s², so we have:

Data:

m = 0.3 kg
g = 9.8 m/s²
h = 15 m
PE = ?

Use formula of potencial energy:

$\boxed{\bold{PE=m*g*h}}$

Replace and solve:

$\boxed{\bold{PE=0.3\ kg*9.8\frac{m}{s^{2}}*15\ m}}$

$\boxed{\boxed{\bold{PE=44.1\ J}}}$

Since the decimal number, that is, the number after the comma is less than 5, it cannot be rounded, then we have this result.

The potential energy of the volleyball is <u>44.1 Joules.</u>

Greetings.

8 0

3 years ago

A sound has a sound level of 30 dB. Its intensity is what multiple of the standard reference level for intensities?

arsen [322]

<h2>Answer:</h2>

1000th multiple of the standard reference level for intensities.

<h2>Explanation:</h2>

The sound intensity level (β), measured in decibels, of a sound with an intensity of I is defined as follows;

β = 10 log (I / I₀) --------------------(i)

Where;

I₀ = reference intensity

Given from the question;

β = sound level = 30dB

Substitute this value into equation (i) as follows;

30 = 10 log (I / I₀)

Divide both sides by 3;

3 = log (I / I₀)

Take antilog of both sides;

10^(3) = (I / I₀)

1000 = I / I₀

Solve for I;

I = 1000I₀

Therefore the intensity of the sound is 1000 times the standard reference level for intensities (I₀)

7 0

3 years ago

If a scale of the solar system was built where 1 mm equaled 1 mile, could the model be practically built in a city?

Y_Kistochka [10]

No, it couldn't be.
On that scale, Neptune would be almost 1,740 MILES from the sun.
ON THAT SCALE !

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3 years ago

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Why is it so important to follow all directions in an experiment?

natita [175]

If you repeat the experiment, you will want to do it the same way to see if the results change.

HOPE THIS HELPS!!!

5 0

2 years ago