What does a cell division allow all multicellular organisms to do

What elements are stars mostly made of? How do we know this?

klemol [59]

Answer:

Mostly made up of Hydrogen and Helium. Spectral analysis of the star light is one of the techniques used to identify the elements.

Explanation:

Stars are made up of lighter elements like hydrogen and helium. The light and heat given out by the stars is due to the thermonuclear reactions that involve the proton proton cycle. Hydrogen fusion reactions forming helium , accompanied by the release of energy happen as a cycle in the core of the star giving it the immense heat , light and temperature.Heavier elements like Carbon, Nitrogen , Oxygen , and iron are also found in some stars.

The elements found in the star are detected using many techniques.. Spectral analysis of the star light is one of the methods that can be used to identify the elements found in the stars.

6 0

3 years ago

A cable that weighs 8 lb/ft is used to lift 900 lb of coal up a mine shaft 650 ft deep. Find the work done. Show how to approxim

Harrizon [31]

Answer:

2275000 lb.ft

Explanation:

Let work done on the cable be denoted by: W_ca

Let work done on the coal be denoted by: W_co

Now, dividing the cable into segments, let x represent the length from top of the mine shaft to the segment.

Meanwhile let δx be the length of the segment.

We are told the cable weighs 8 lb/ft. Thus;

Work done on one segment = 8 × δx × x = 8x•δx

Therefore, work done on cable is;

W_ca = ∫8x•δx between the boundaries of 0 and 650

Thus;

W_ca = 4x² between the boundaries of 0 and 650

W_ca = 4(650²) - 4(0²)

W_ca = 1,690,000 lb.ft

Workdone on the 900 lb of coal will be calculated as;

W_co = 900 × 650

W_co = 585000 lb.ft

Thus,

Total work done = W_ca + W_co

Total workdone = 1690000 + 585000

Total workdone = 2275000 lb.ft

6 0

3 years ago

Please help me this is a test and it needs to be done in a few

Amanda [17]

Answer:

I think A because astroids are stronger than a crash. Hope I helped! :)

Explanation:

7 0

4 years ago

Read 2 more answers

Covalent Bonds usually bond atoms of which type of elements together?

anzhelika [568]

<h2>Answer: Nonmetals to Nonmetals </h2>

Covalent bonds hold non-metallic atoms together. These atoms have many electrons in their outermost level and have a tendency to gain electrons rather than to yield them.

In this case the bond is formed by sharing a pair of electrons between the two atoms, one from each atom. Then, this pair of shared electrons is common to the two atoms and holds them together, so that both atoms acquire more stability.

Therefore the correct answer is C.

5 0

4 years ago

An egg is Free Falling Down from a nest in a tree (neglect air resistance)

DedPeter [7]

We are to calculate the acceleration.

Answer:

-9.8 m/s²

Explanation:

Since the egg is in a free fall, it means that the force due to gravity will be equal to the normal force.

Now,

Force due to gravity: F_g = mg

Normal force; F_n = ma

Thus;

mg = ma

m will cancel out to get

g = a

Since it is a free fall motion, then gravity is negative;

-g = a

g has a constant value of 9.8 m/s². Thus;

a = -9.8 m/s²

5 0

3 years ago