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A given star has a peak emission wavelength of 60nm, lies 7.10*10^19m away and the intensity of its electromagnetic radiation reaching the Earth is 3.33*10^-8Wm^-2. Calculate the star's diameter

With a problem like this, the key is to split it down into component parts. We will treat the star as a perfect emitter and radiator, something known as a black body. There will be two physical laws we need ...
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Answered by James S. • Physics tutor
5049 Views

What is a mole?

In chemistry the mole (mol) is a basic unit to describe a quantity of substance based on the number of particles (atoms or molecules) that it contains. The number of particles in one mole of substance is 6.0...
TP
Answered by Tomos P. • Chemistry tutor
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basics of past tenses in Spanish - What is the difference between the Preterite and Imperfect?

We'll begin with how to form (or conjugate if we're being fancy) the preterite & imperfect tenses. IR – TO GO (THIS IS A SPECIAL IRREGULAR ONE YOU NEED TO LEARN) Preterite Imperfect Fui Iba Fuiste Ibas F...
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Answered by Rose H. • Spanish tutor
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Who was responsible for the outbreak of the Cold War?

Who was responsible for the outbreak of the Cold War? Was America responsible? · President Truman’s use of the atomic bomb in Japan could be seen as a threat, especially as he did not tell Stalin about it be...
JN
Answered by Joanna N. • History tutor
10027 Views

What is the cosine rule and when can it be used?

The cosine rule is used to find the length of a side or size of an angle. Take a look at the triangle below: For this triangle we have sides a, b and c and angles A,B and C. For this triangle the cosine rule...
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Answered by Kulvinder L. • Maths tutor
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