Answer:
Space junk is travelling so fast that a collision with an astronaut or a spacecraft could be disastrous.
Explanation:
Space junk orbits the Earth at speeds of about 28 000 km/h.
That's so fast that even an orbiting fleck of paint has enough kinetic energy to cause impact craters on the surface of a spacecraft. They are even more dangerous to an astronaut on a space walk.
Much of the space debris is larger and more dangerous than a fleck of paint.
One rough estimate of the amount of space debris is
<em> </em><u>Size</u><em> </em> <u>Number of objects</u>
< 1 cm 200 000 000
1 cm to 10 cm 700 000
> 10 cm 30 000
Satellites, etc. 18 000
The chances of collision are small, but any collision can be disastrous.
Answer:
69.7% is percent yield
Explanation:
Based on the reaction:
3Ca(NO3)2(aq) + 2Na3PO4(aq) → Ca3(PO4)2(s) + 6NaNO3(aq)
2 moles of Na3PO4 react producing 6 moles of NaNO3.
As 24.2 moles of Na3PO4 react, theoretical moles of NaNO3 produced are:
24.2 moles Na3PO4 * (6 moles NaNO3 / 2 moles Na3PO4) =
72.6 moles of NaNO3
As there are produced 50.6 moles of NaNO3, percent yield is:
50.6 moles NaNO3 / 72.6 moles NaNO3 =
<h3>69.7% is percent yield</h3>
Layer 2 and layer 9 are the same relative age.
Explanation:
The statement that best describes the rock layers is that Layer 2 and layer 9 are the same relative age..
The relative age is used in placing sedimentary rocks in order of their occurrence.
To do this, we apply the sedimentary laws.
The ones applicable here are:
- Principle of superposition states that in an undisturbed sequence, the oldest layer is at the base and youngest on top.
- Principle of cross cutting states that a fault and intrusion are younger than the rocks they cut through.
- Principle of fossil and fauna succession states that fossils and fauna succeed on another in a determinable form.
We see that layers 2 and 9 have the same fossil and are the same lithological units.
learn more:
Sedimentary rocks brainly.com/question/2740663
#learnwithBrainly
