Choice 1 
The Sun's radiation and solar wind cause the dust and gas around the comet (coma) to stretch the coma. The solar wind electromagnetically blows the ions in the coma away.
 
        
             
        
        
        
Explanation:
Fluid gauge pressure is:
P = ρgh
where ρ is the fluid density and h is the depth of the fluid.
P = (1000 kg/m³) (9.8 m/s²) (1642 m)
P = 16,091,600 Pa
Rounded to four significant figures, the gauge pressure is 16.09 MPa.
 
        
             
        
        
        
Answer:
Explanation:
(A) True: It is true.
In junction law, the current entering at a junction is equal to teh current leaving at the junction.
(B) False: It is false.
The kirchhoff's junction law is based on the conservation of charge. 
(C) True: It is true.
Energy is used in the circuit.
(D) True: It is true.
It is based on the conservation of charge. 
 
        
             
        
        
        
Answer:
The answer to your question is: D.
Explanation:
Distance refers to the amount of space between two points, it is a scalar quantity. 
Displacement refers to the space between two points, measure from the minimum path linking them, it is a vector quantity.
I'm not agree with these answers, because the total distance  is approximately 500km.
A) The distance traveled is 300 km.  This answer is not correct. 
B) Distance is 300 km and displacement is 0 km.  This answer is not correct because the displacement is also 500 km.
C) Distance is 300 km/hour and displacement is 300 km.
 300 km/h is a measure of speed not of distance, this option is wrong.
D) Both distance traveled and displacement are 300 km. I think this is the correct answer because distance and displacement measure the same. but I think both measure 500 km.