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2 years ago

10

I am no out of points for i have been giving them all away

2 answers:

Blababa [14]2 years ago

7 0

Answer: ok

Explanation:

Vsevolod [243]2 years ago

3 0

Thank you kind person

*hands you a whole gallon of ketchup :)))

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Can somebody please help me? PLEASE

ale4655 [162]

Answer:

The 1st Answer

Explanation:

Because kinetic energy is the energy which a body possesses by virtue of being in motion. So if the velocity of the object (cannonball in this case) decreases than so would the kinetic energy

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2 years ago

To calculate the heat needed to melt a block of ice at its melting point what do you need to know

Alisiya [41]

You have to know what the temperature of your suroundings first and then you can melt it with the tools you need. yeah that's another thing know what tools you need and then be safe!:D

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2 years ago

A concert loudspeaker suspended high off the ground emits 28.0 W of sound power. A small microphone with a 0.700 cm2 area is 55.

grandymaker [24]

Explanation:

It is known that wave intensity is the power to area ratio.

Mathematically, I = $\frac{P}{A}$

As it is given that power is 28.0 W and area is $7 \times 10^{-5} m^{2}$ .

Therefore, sound intensity will be calculated as follows.

I = $\frac{P}{A}$

= $\frac{28.0 W}{4 \times 3.14 \times 7 \times 10^{-5} m^{2}}$

= $0.318 \times 10^{5} W/m^{2}$

or, = $3.18 \times 10^{4} W/m^{2}$

Thus, we can conclude that sound intensity at the position of the microphone is $3.18 \times 10^{4} W/m^{2}$ .

7 0

2 years ago

2. What is one reason why the author includes information about religious beliefs during the time of Johannes Fabricius' discove

Lesechka [4]

B. to show that there was conflict between what scientists were observing about the universe and what religion taught them

8 0

2 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