Of the two forms of friction you studied,_____ friction is the one that must be overcome in order to start something moving.

which process was found after wegeners time, helped scientists find out how the continents actually move.

Genrish500 [490]

I don't quite know what you're asking so I'll just go on a rant :) Wegener created and supported the continental drift theory, which stated that all of the continents once formed a super continent called Pangea. No one at the time believed in the theory though so he spent the rest of his life trying to find evidence to prove it. However, after he died scientists began to find information that supported his theory. When scientists began to study Earth's surface and the layers below, the theory of the tectonic plates was formed. This theory stated that Earth's crust, the lithosphere, was divided into twelve moving plates. This theory did in fact prove that Wegener's theory was correct. Another theory that proved Wegener's theory to be true was the process of Sea Floor Spreading. This theory stated that at divergent plate boundaries, new ocean floor was being created and the old was being pushed away from the boundary, the old sea floor would then be pushed to deep sea trenches created by convergent plate boundaries and essentially recycled back into the Earth. I hope this helped, sorry it is so long :)

6 0

3 years ago

Some hypothetical alloy is composed of 12.5 wt% of metal A and 87.5 wt% of metal B. If the densities of metals A and B are 4.27

densk [106]

Answer:

The number of atoms in the unit cell is 2, the crystal structure for the alloy is body centered cubic.

Explanation:

Given that,

Weight of metal A = 12.5%

Weight of metal B = 87.5%

Length of unit cell = 0.395 nm

Density of A = 4.27 g/cm³

Density of B= 6.35 g/cm³

Weight of A = 61.4 g/mol

Weight of B = 125.7 g/mol

We need to calculate the density of the alloy

Using formula of density

$\rho=n\times\dfrac{m}{V_{c}\times N_{A}}$

$n=\dfrac{\rho\timesV_{c}\times N}{m}$ ....(I)

Where, n = number of atoms per unit cells

m = Mass of the alloy

V=Volume of the unit cell

N = Avogadro number

We calculate the density of alloy

$\rho=\dfrac{1}{\dfrac{12.5}{4.27}+\dfrac{87.5}{6.35}}\times100$

$\rho=5.98$

We calculate the mass of the alloy

$m=\dfrac{1}{\dfrac{12.5}{61.4}+\dfrac{87.5}{125.7}}\times100$

$m=111.15$

Put the value into the equation (I)

$n=\dfrac{5.9855\times(0.395\times10^{-9}\times10^{2})^3\times6.023\times10^{23}}{111.15}$

$n=1.99\approx 2\ atoms/cell$

Hence, The number of atoms in the unit cell is 2, the crystal structure for the alloy is body centered cubic.

5 0

3 years ago

Why are there only two elements in the first period of the periodic table?(1 point)

Katen [24]

Answer:

because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits

6 0

2 years ago

An atomic physicist determines that an atom is composed of 8 positively charged particles and has a mass of 15 amu. which is the

stellarik [79]

<span> 1.the atom has 7 neutrons and 8 protons....

because the positively charged particles are the protons ...and 8 is also the atomic number ...so number of neutrons can be calculated by subtracting </span>atomic number from the mass number...which gives us the neutrons 7 ...

Hope it helps !!!

5 0

3 years ago

Read 2 more answers

What did scientists create using scientific measurements?

Alexxx [7]

Answer:

lines?

Explanation:

3 0

3 years ago

Of the two forms of friction you studied,_____ friction is the one that must be overcome in order to start something moving.​

Of the two forms of friction you studied,_____ friction is the one that must be overcome in order to start something moving.