What is the last planet discovered?

Which of the following elements is commonly found in the Earth's crust, living matter, oceans, and atmosphere? A. carbon B. argo

jekas [21]

The answer is carbon.

8 0

3 years ago

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Ear "popping" is an unpleasant phenomenon sometimes experienced when a change in pressure occurs, for example,in an airplane. If

marshall27 [118]

Answer:

H = 0.00058m = 0.58mm of Mercury

h = 160m for popping at 8000m

Explanation:

Air density decreases with altitude (increasing height).

At sea level air density = 1.22kg/m^3

while at 3000m above it is approximately 0.8 kg/m^3

ASSUMPTION:

we neglect the change in density across 100m vertically

density of mercury = 13600kg/m ^3

we equate the pressure for mercury and air

AIR(pgh) = Mercury(pgh)

0.8 * g * 100 = 13600 * g * H

H = 0.00058m = 0.58mm of Mercury

At even farther heights, the air density further drops

at 8000m above it is 0.52kg/ m^3 (source:https://www.engineeringtoolbox.com/standard-atmosphere-d_604.html)

***for the ear to pop again, it has to experience same change in pressure as of at 3000m

Change in P for AIR at 3000m = Change in P for AIR at 8000m

ASSUMPTION : gravitational acceleration does not change with altitude

pgh = pgh

0.8 * g * 100 = .5 * g *h

h = 160m

3 0

4 years ago

A nuetral atom has no overall charge. Explain this in terms of its particles.

agasfer [191]

Firstly an atom has electrons , protons and neutrons. The protons are positively charged and the electrons are negatively charged and the neurons are neutral. So in a neutral atom the amount of protons equals to the amount of electrons. Thus the protons and neutrons can be called particles

6 0

4 years ago

Explain the limitations of electrical energy production created exclusively by renewable energy sources.

Diano4ka-milaya [45]

Answer:

The main limitation while the production of electrical energy is that the source from which electrical energy products cannot be available all the time

Explanation:

The main limitation while the production of electrical energy is that the source from which electrical energy products cannot be available all the time. There can be many factors that can hinder the availability of the source. for example, the Availability of solar energy can be hindered due to the cloud.

one the other important thing that needs to be taken into consideration is that although renewable energy is considered to be environment-friendly but to rely on this point cannot be true always

5 0

3 years ago

A hammer taps on the end of a 3.8-m-long metal bar at room temperature. A microphone at the other end of the bar picks up two pu

Elan Coil [88]

Answer:

the speed of sound in this metal is 1668 m/s

Explanation:

given information:

x = 3.8 m

t = 8.80 ms = 0.0088 s

the speed of sound in the metal

v = x/Δt

to find the Δt of the metal, we have to calculate the interval time sound in the air

$t_{air}$ = x/ $v_{air}$ , $v_{air}$ = 343 m/s

so,

$t_{air}$ = 3.8/343 = 0.01108 s

Δt = $t_{air}$ - t

= 0.011079 - 0.0088

= 0.002279

v = x/Δt

= 3.8/ 0.002279

= 1668 m/s

8 0

4 years ago