Electrons are negatively charged and are found outside in the nucleus in the rings surrounding the nucleus.
        
                    
             
        
        
        
Answer:
I know one answer is an observer on earth sees a lunar eclipse
 
        
                    
             
        
        
        
1. calculate the value of acceleration that objects gains in that period of time 
•calculating acceleration 
5.50 = 1/2at^2 
5.50*2/t^2 = a
11.00/0.657 = a
16.74=a 
now you got the acceleration
2. you have laws of gravitation for that
g = Gm/r^2
where g is the acceleration value 
16.74 = 6.754*10^-11 × m/ 6.28*10^4
105.14*10^4 /6.754*10-11 = m
15.567*10^15 = m 
that would be the mass of the planet ...
        
                    
             
        
        
        
Answer:
350.72 m/s
Explanation:
Formula for velocity of wave is;
v = fλ
Where;
v is speed
f is frequency 
λ is wavelength 
We are given;
f = 512 Hz
λ = 0.685 m
Thus;
v = 512 × 0.685
v = 350.72 m/s
 
        
             
        
        
        
v = x/t
v = average velocity, x = displacement, t = elapsed time
Given values:
x = 6km south, t = 60min
Plug in and solve for v:
v = 6/60
v = 0.1km/min south