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Gwar [14]
3 years ago
6

Astronomers use the _______ of stars to determine how hot they are and their _______ to estimate how far away they are. A. brigh

tness; size B. temperature; position C. size; temperature D. color; brightness
Physics
1 answer:
ss7ja [257]3 years ago
6 0

Astronomers use the color of stars to determine how hot they are and their brightness to estimate how far away they are. <em>(D)</em>

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Please help i'm going to throw up from stress
Eddi Din [679]

Answer:

Explanation:

First of all, I used the specific heat of water as 4182 J/(kgC) and the specific heat of ethyl alcohol (EtOH) as 2440 J/(kgC); that means that we need the masses in kg, not g.

120.g = .1200 kg of ethyl alcohol. Now for the formula:

t_f=\frac{(m_{H2O}*spheat_{H2O}*temp_{H2O})+(m_{EtOH}*spheat_{EtOH}*temp_{EtOH})}{(m_{H2O}*spheat_{H2O})+(m_{EtOH}*spheat_{EtOH})} where spheat is specific heat.

Filling that horrifying-looking formula in with some values:

16.0=\frac{(x*4182*20.0)+(.1200*2440*10.0)}{(x*4182)+(.1200*2440)} and

16.0=\frac{83640x+2928}{4182x+292.8} and

16(4182x + 292.8) = 83640x + 2928 and

66912x + 4684.8 = 83640x + 2928 and

1756.8 = 16728x so

x = .105 kg and the amount of water added is 105 g

4 0
3 years ago
At what speed, as a fraction of c , is a particle's total energy twice its rest energy
WINSTONCH [101]
The rest energy of a particle is
E_0=m_0 c^2
where m_0 is the rest mass of the particle and c is the speed of light.

The total energy of a relativistic particle is
E=mc^2 =  \frac{m_0 c^2}{ \sqrt{1- \frac{v^2}{c^2} } }
where v is the speed of the particle.

We want the total energy of the particle to be twice its rest energy, so that
E=2E_0
which means:
\frac{m_0c^2}{ \sqrt{1- \frac{v^2}{c^2} } }=2m_0 c^2
\frac{1}{ \sqrt{1- \frac{v^2}{c^2} } }=2
From which we find the ratio between the speed of the particle v and the speed of light c:
\frac{v}{c}=  \sqrt{1- (\frac{1}{2})^2 }  =0.87
So, the particle should travel at 0.87c in order to have its total energy equal to twice its rest energy.
3 0
3 years ago
Which part of the electromagnetic spectrum is nearest to radio waves?
Sav [38]

Answer:

i believe it is the microwaves that is closest to the radio waves.

Explanation:

8 0
2 years ago
Read 2 more answers
Caleb rides his horse with a constant speed of 12 miles per hour. How far can she travel in 3 1/2 hours?
baherus [9]
12 × 3= 36
12 × 1/2 = 6
36+ 6= 42
6 0
3 years ago
If you drop a 50 gram piece of metal that has a temperature of 110°Celsius into 1000 grams of water at 25°Celsius, what best des
LuckyWell [14K]
If you drop a 50 gram piece of metal that has a temperature of 110°Celsius into 1000 grams of water at 25°Celsius, <span>D.)The water and the metal’s temperature will reach the same temperature. In any system undergoing heat transfer, the objects involved will eventually reach the same temperature, signifying thermal equilibrium.</span>
7 0
2 years ago
Read 2 more answers
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