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grandymaker [24]
3 years ago
5

Twenty is the _________________ of potassium

Physics
1 answer:
Mumz [18]3 years ago
7 0
Twenty is the atomic number of potassium.
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We know that the magnitudes of the negative charge on the electron and the positive charge on the proton are equal. Suppose, how
TEA [102]

Answer:3,45 x 10^9 N

Explanation: We have considered the total charge for each coin , this is the total atoms x 29 electrons for cooper and multiplier by electron charge, the total charge for each coin is 0,464 C

Finally we use the Coulomb law,

F=k Q/ (r)^2

6 0
2 years ago
5. Dry ice is an example of _________, which is the process of a solid turning directly into a gas. (1 point) precipitation melt
ki77a [65]
<span>5. Dry ice is an example of _________, which is the process of a solid turning directly into a gas. (1 point)

sublimation


6. The ____ is a unit of force. (1 point)

</span>n<span>ewton

7. Which of the following is the boiling point of water? (1 point)
 
100°C 


8. Which of the following describes the molecular structure of water at 40°C? (1 point)

water molecules are close together and moving freely around each other </span>
6 0
3 years ago
Which of the following best describes the human population from early times to the present?
Makovka662 [10]

Answer:

We have a not significant increase of the population until 1700s or 1800s and then a significant increase growth from these years to the present.

Explanation:

From the figure attached we see the evolution of the human population since early times (1050).

We see that from 1050 until 1750-1850 we have an increase slowly with a low value for the increase per year.

But after these years (1750-1850) we see a considerable increase of the population, like an exponential model.

So then we can conclude in general terms this:

We have a not significant increase of the population until 1700s or 1800s and then a significant increase growth from these years to the present.

7 0
2 years ago
The pressure drop needed to force water through a horizontal 1-in diameter pipe if 0.60 psi for every 12-ft length of pipe. Dete
oksian1 [2.3K]

Answer:

The shear stress at a distance 0.3-in away from the pipe wall is 0.06012lb/ft²

The shear stress at a distance 0.5-in away from the pipe wall is 0

Explanation:

Given;

pressure drop per unit length of pipe = 0.6 psi/ft

length of the pipe = 12 feet

diameter of the pipe = 1 -in

Pressure drop per unit length in a circular pipe is given as;

\frac{\delta P}{L} = \frac{2 \tau}{r} \\\\

make shear stress (τ) the subject of the formula

\frac{\delta P}{L} = \frac{2 \tau}{r} \\\\\tau = \frac{\delta P *r}{2L}

Where;

τ is the shear stress on the pipe wall.

ΔP is the pressure drop

L is the length of the pipe

r is the distance from the pipe wall

Part (a) shear stress at a distance of  0.3-in away from the pipe wall

Radius of the pipe = 0.5 -in

r = 0.5 - 0.3 = 0.2-in = 0.0167 ft

ΔP = 0.6 psi/ft

ΔP, in lb/ft² = 0.6 x 144 = 86.4 lb/ft²

\tau = \frac{\delta P *r}{2L}  = \frac{86.4 *0.0167}{2*12} =0.06012 \ lb/ft^2

Part (b) shear stress at a distance of  0.5-in away from the pipe wall

r = 0.5 - 0.5 = 0

\tau = \frac{\delta P *r}{2L}  = \frac{86.4 *0}{2*12} =0

3 0
3 years ago
According to the law of mass, 8 grams of hydrogen and 32 grams of oxygen will combine to form how many grams of water?
seropon [69]

Answer:

36 grams of water

Explanation:

mass of H2O = 0.5 x 18 = 9g

7 0
2 years ago
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