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2 years ago

Which statements describe properties of stars? Check all that apply.

2 answers:

7 0

One, three and five are correct.

Although if the second statement is saying that stars use gravitational force to support nuclear fusion which in turn produces energy then that would be correct, but I don’t think so :)

swat322 years ago

4 0

Answer:

Stars produce energy through nuclear fusion.
Stars are massive objects composed of gas.
Stars are composed primarily of hydrogen and helium.

Explanation:

Stars are massive objects that have a large gravitational field, which drives the star to contract on itself, which is why fusion occurs: in the center of the star the nuclei of atoms are already so close due to gravity and high temperatures that bind. This is what is called nuclear fusion and is the energy source of a star.

On the other hand yes, the main elements of a star are hydrogen and helium (two hydrogen nuclei fuse to make helium), this makes the star mainly a huge ball of gas so there is no solid surface where you can stand on.

And about water on a star, that is not possible. Temperatures on stars are very vey high that watter could not exist in a liquid form on them.

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cual seria el consumo semanal de un refrigerador que esta encendido 12 horas diarias con una potencia de 0.8kw

aniked [119]

Answer:

jajajaja sorry no ablaru inglich jajj yes or nou?

4 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

Any one please give me the correct answer of this question???<br> I hope you can help me...

Phantasy [73]

Answer:

no one ever amswers my questions

3 0

3 years ago

Oil tends to float on water because the density of oil is _____ the density of water.

Rama09 [41]

Oil is less dense than water so it tends to float on the top of the water. Hope this Helps!

7 0

3 years ago

A bullet with a mass of 5 gramsand speed of 560 m/sis fired horizontally atablock of wood with a mass of 2 kg. The block rests o

Anni [7]

Momentum is conserved if and only if sum of all forces which are exserted on system equals zero. In our situation there are only internal forces, so by Newton's third law their vector sum is 0.

So $mv=(m+M)v' \Leftrightarrow v'=\frac{mv}{m+M}$ .

Kinetic energy of system at first: $\frac{mv^2}{2}=784\;\textbf{J}$ . After: $\frac{(m+M)\frac{m^2v^2}{(m+M)^2} }{2}=\frac{m^2v^2}{2(m+M)}\approx 1,96\; \textbf{J}$ . The secret is that other energy is in work of deformation forces (they in turn heat a bullet and a block).

Answer is A)

5 0

3 years ago