Answer:
The maximum theoretical height that the pump can be placed above liquid level is 
Explanation:
To pump the water, we need to avoid cavitation. Cavitation is a phenomenon in which liquid experiences a phase transition into the vapour phase because pressure drops below the liquid's vapour pressure at that temperature.  As a liquid is pumped upwards, it's pressure drops. to see why, let's look at Bernoulli's equation:

( stands here for density,
 stands here for density,  for height)
 for height)
Now, we are assuming that there aren't friction losses here. If we assume further that the fluid is pumped out at a very small rate, the velocity term would be negligible, and we get:


This means that pressure drop is proportional to the suction lift's height. 
We want the pressure drop to be small enough for the fluid's pressure to be always above vapour pressure, in the extreme the fluid's pressure will be almost equal to vapour pressure.
That means:

We insert that into our last equation and get:

And that is the absolute highest height that the pump could bear. This, assuming that there isn't friction on the suction pipe's walls, in reality the height might be much less, depending on the system's pipes and pump.
 
 
        
             
        
        
        
Answer:
<h2>Steel</h2>
Explanation:
Steel is the metal that using in planes.
Aluminum and titanium also used in this aircraft industry.
Aluminum is ideal for aircraft manufacture because it's lightweight and strong. 
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Answer:
The lunar radiation environment, allowing scientists to determine potential impacts to astronauts and other life. It also will test models on the effects of radiation and measure radiation absorption by a type of plastic that is like human tissue. The results could aid in the development of protective technologies to help keep future lunar crew members safe. CRaTER was built and developed by Boston University and the Massachusetts Institute of Technology in Boston.