PHYSICS
COLLEGE

Answer:

Answer:

(a)

(b)

Explanation:

(a) 1 mile is equal to 1.609344 kilometers. So, we have:

(b) 1 mile is equal to 1609.34 meters. 1 hour is equal to 3600 seconds. So, we have:

MIDDLE SCHOOL

Why is silicon needed in solar panels?

Hi, silicon is essential in solar panels because, silicon is a semiconductor material (meaning a solid substance that has a conductivity of an insulator and is an essential component of most electric circuits ) now, when dipped with impurities such as gallium and arsenic it has the ability to capture the suns energy and convert to electricity. hope this is helpful if it is than put a thank you plz.

HIGH SCHOOL

The emissivity of galvanized steel sheet, a common roofing material, is 0.13 at temperatures around 300 K, while its absorptivity for solar irradiation is S 0.65. Would the neighborhood cat be comfortable walking on a roof constructed of the material on a day when GS 750 W/m2, T 16 C, and h 7 W/m2 K? Assume the bottom surface of the steel is insulated.

In the given situation, the cat would not be comfortable walking on a roof because its surface temperature is 77.17°C which can even cause burns to its paws.

How does calculate the rate of heat transfer?The total heat transfer rate can be defined as the combined convection and radiation transfer rate, multiplied by the absorptivity factor. From that equation, we can find the temperature of the roof using the iteration method.

Given, the emissivity of galvanized steel sheet, ∈ = 0.13

The absorptivity of the steel sheet roof = 0.65

The air temperature 16°C = 16 + 273 = 289K

The rate of heat transfer = 750 W/m²

The natural convection, h = 7W/m²K

The total heat transfer rate is the combined heat transfer of convection and radiation:

After substituting the values in the above equation:

By using the iteration method:

Therefore, the cat should not be comfortable walking on a roof as its surface temperature is 77.17°C. Her paws can be burned.

Learn more about rate of heat transfer, here:

brainly.com/question/21043668

#SPJ5

Answer:

Total heat transfer rate is combined convection and radiation transfer rate, multiplied with absorptivity factor. From that equation you can find temperature of the roof using iteration method.

Explanation:

Known:

steel sheet roof emissivity ∈ = 0.13

steel sheet roof absorptivity _s = 0.65

air temperature T∞ = 16°C ...= 289K

heat transfer rate = 750 W/m2

natural convection h = 7W/m2K

Total heat transfer rate is combined heat transfer rate of convection and radiation, multiplied with absorptivity factor:

=T∞-)+∈σA(

-T∞)-∈σ(=0

2562-7-7.371*10^-9=0

Use iteration method to solve for

=350.17 K...=77.17°C

In this particular situation, cat would not be comfortable with walking on a roof since its surface temperature is 77.17°C which may even cause burns to its paws.

HIGH SCHOOL

Now consider a wave which is paired with seven other waves into seven pairs. The two waves in each pairing are identical, except that one of them is shifted relative to the other in the pair by the distance shown:A. -(1/2) ?B. 2?C. -5?D. (3/2)?E. 0F. (17/2)?G. (6/2)?Identify which of the seven pairs will interfere constructively and which will interfere destructively. Each letter represents a pair of waves.Enter the letters of the pairs that correspond to constructive interference in alphabetical order and the letters of the pairs that correspond to pairs that interfere destructively in alphabetical order separated by a comma. For example if pairs A, B and D interfere constructively and pairs C and F interfere destructively enter ABD,CF.

The pair BCEG will interfere constructively, while the pair ADF will interfere destructively.

Constructive and destructive interference:For interference, the waves must be coherent.

Two coherent waves interfere constructively when the path difference is equal to an integral multiple of the wavelength.

That is the path difference must be mλ

where m = 0,1,2,3.... is an integer and λ is the wavelength

So pair BCEG interfere constructively

Two coherent waves interfere destructively when the path difference is equal to a half-integral multiple of the wavelength.

That is the path difference must be (m+1/2)λ

where m = 0,1,2,3.... is an integer and λ is the wavelength

So pair ADF interfere destructively

Learn more about interference:

brainly.com/question/1194044?referrer=searchResults

Answer:

BCEG,ADF

Explanation:

Between 2 waves, if path difference is mλ, m is an integer and they interfere constructively.

Between 2 waves, if path difference is (m+1/2)λ, m is an integer and they interfere destructively.

BCEG,ADF

MIDDLE SCHOOL

A physicist wants to examine the characteristics of the new material the physicist will most likely do so by what method? A survey a group of people

B perform fieldwork in a remote location

C perform laboratory experiments

D make observations of an ecosystem

PLEASE EXPLAIN ANSWER

C, beacuse when you experiment you can also observe it and laboratory experiments help you discover new matrials