Answer:
A. 
Explanation:
Earth is composed of different layers and one layer moves over another due to differences in the densities.
According to the physics of density, a substance having less density floats over a higher density substance. The oceanic crust has more density than the continental crust that is why continental crust float over oceanic crust. 
So in the given example, plate B is moving below the plate A, it means plate B is more dense than plate A because plate B is composed of oceanic crust
. <u>For example : continents float over the asthenosphere (a layer below the lithosphere).</u>
Hence, the correct answer is "A
".
 
        
             
        
        
        
Answer: The volume is decreasing at a rate of 80 cm3/min
Explanation: Please see the attachments below
 
        
             
        
        
        
1,000 W  =  1 kW 
100 W  =  0.1 kW
           (0.1 kW) x (6 h) = 0.6 kWh    <=== energy
           (0.6 kWh) x (£0.1359/kWh)  =  £0.0815     <=== cost of it      
        
             
        
        
        
Drag from her armas would slow her down if she was spinning at a fast speed
        
             
        
        
        
Answer:
Principal quantum numbers are denoted by the symbol 'n'. They designate the principal electron shell of the atom. The positive whole number values starting from 1,2,3 and so on..
Explanation:
All orbitals that have the same value of n are said to be in the same shell (level). For a hydrogen atom with n=1, the electron is in its ground state; if the electron is in the n=2 orbital, it is in an excited state. The total number of orbitals for a given n value is n2.