All categories

4 years ago

According to theory, all of the elements, except for Hydrogen and Helium, originated from the life and death of a ___________.

Physics

2 answers:

butalik [34]4 years ago

4 0

Answer: STAR

Explanation:

Present theory is that hydrogen and some helium (not all helium) condensed after the initial cooling of the "Big Bang". As the universe continued to expand and cool, clouds of hydrogen, et.al., began to coalesce into dense objects we presently call stars. The pressure due to gravitonal attraction became so much, the hydrogen was heated and was able to fuse together via quantum tunneling, and form other elements. Some of these other elements continued to fuse into ever larger elements. As the fusion process reached an end, death of the star caused explosions known at supernovas. The extra pressure caused by these explosions are responsible for all the elements we have today. Some of the heaviest elements may only be "born" of stars of the proper mass.

Ksenya-84 [330]4 years ago

3 0

A... star im pretty sure

You might be interested in

you stand on a straight desert road at night and observe a vehicle approaching. this vehicle is equipped with two small headligh

inysia [295]

Answer:

The distance that you marginally able to discern that there are two headlights rather than a single light source is 6.084 km

Explanation:

Given:

d = distance = 0.679 m

λ = wavelength of the light = 537 nm = 537x10⁻⁹m

dp = pupil diameter = 4.81 mm = 0.00481 m

Question: What distance, in kilometers, are you marginally able to discern that there are two headlights rather than a single light source, dx = ?

For the separation of the peak from the central maximum it is:

$sin\theta =\frac{\lambda }{d_{p} } =\frac{537x10^{-9} }{0.00481} =1.116x10^{-4}$

In this case, the two small sources of the headlights have the same angle as the images that form inside the eye

$d_{x} =\frac{d}{sin\theta } =\frac{0.679}{1.116x10^{-4} } =6.084x10^{3} m=6.084km$

7 0

4 years ago

A girl (mass M) standing on the edge of a frictionless merry-go-round (radius R, rotational inertia I) that is not moving. She t

vladimir1956 [14]

a) $\omega=\frac{-mvR}{I+MR^2}$

b) $v=\frac{-mvR^2}{I+MR^2}$

Explanation:

Since there are no external torques acting on the system, the total angular momentum must remain constant.

At the beginning, the merry-go-round and the girl are at rest, so the initial angular momentum is zero:

$L_1=0$

Later, after the girl throws the rock, the angular momentum will be:

$L_2=(I_M+I_g)\omega +L_r$

where:

$I$ is the moment of inertia of the merry-go-round

$I_g=MR^2$ is the moment of inertia of the girl, where

M is the mass of the girl

R is the distance of the girl from the axis of rotation

$\omega$ is the angular speed of the merry-go-round and the girl

$L_r=mvR$ is the angular momentum of the rock, where

m is the mass of the rock

v is its velocity

Since the total angular momentum is conserved,

$L_1=L_2$

So we find:

$0=(I+I_g)\omega +mvR\\\omega=\frac{-mvR}{I+MR^2}$

And the negative sign indicates that the disk rotates in the direction opposite to the motion of the rock.

The linear speed of a body in rotational motion is given by

$v=\omega r$

where

$\omega$ is the angular speed

r is the distance of the body from the axis of rotation

In this problem, for the girl, we have:

$\omega=\frac{-mvR}{I+MR^2}$ is the angular speed

$r=R$ is the distance of the girl from the axis of rotation

Therefore, her linear speed is:

$v=\omega R=\frac{-mvR^2}{I+MR^2}$

5 0

3 years ago

Forces can be________. What phrase completes the sentence.

koban [17]

Answer:

pushes or pulls

Explanation:

hope this helps....

7 0

3 years ago

Can you help me please

Rufina [12.5K]

Answer:

Explanation:

6 0

3 years ago

What is an example of density

Taya2010 [7]

Ice floating on water and Ice floats on water because it is less dense than water. Things that are less dense float on top of things that are more dense because molecules in ice are further apart than molecules in water.

5 0

3 years ago