Use the formula dgh + p atm
d is density g is gravitational field strength h heigh or depth and p atm is atmospheric pressure 
1000 x 10 x 20 + 100000 = 300000
almost 300,000 pascal
        
             
        
        
        
Kepler noticed an imaginary line drawn from a planet to the Sun and this line swept out an equal area of space in equal times, If we then draw a triangle out from the Sun to a planet’s position at one point in time, it is notice that the area doesn't change even after the planet has left the original position say like after 2 to 3days or 2hours. So to have same area of triangle means that the the planet move faster when that are closer to the sun and slowly when they are far from the sun. 
This led to Kepler's law of orbital motion.
First Law: Planetary orbits are elliptical with the sun at a focus.
Second Law: The radius vector from the sun to a planet sweeps equal areas in equal times.
Third Law: The ratio of the square of the period of revolution and the cube of the ellipse semi-major axis is the same for all planets.
It is this Kepler's law that makes Newton to come up with his own laws on how planet moves the way they do.
 
        
             
        
        
        
Answer:
b. negative
Explanation:
neutrons have a negative charge and protons have a proton has a positive charge 
 
        
                    
             
        
        
        
Answer:
low risk for tissue damage
uses radio waves
the last three are not correct 
:)