Answer:
7.19 * 10^14J
Explanation:
Given that 
Density of water Pwater= 1000kg/m3
R=2.1km = 2.1*10^3m
H= 2.3cm. = 2.3*10^-2m
Lv water= 2256 * 10^3J/kg
First, mass of water need to be calculated, using an imaginary cylinder
Density= Mass /Volume
Mass= Density* Volume
Volume of a cylinder= πR2h
Therefore mass= PπR2H
 = 1000 * π * (2.1 *10^3)^2 * (2.3 * 10^-2)
 = 3.18 *10^8
Heat Released Qv = mLV
 = 3.18*10^8 * 2236*10^3
 = 7.19 * 10^14J
 
        
                    
             
        
        
        
Answer:
C. An ion with a +2 charge
Explanation:
I guess
 
        
                    
             
        
        
        
It spins one bc it takes 365 days to make a year and to make a year the earth has to mov some
        
                    
             
        
        
        
Work = (force) x (distance)
80 J = (force) x (4 m)
Force = (80 J) / (4 m)  =  20 N
That's IF the force was in the same direction as the 4m of motion.
If the force was kind of slanted, then it had to be stronger, and
it had a component of 20N in the direction of the motion.