Gas "floats" so if there are examples or pictures it would be the one with the most evenly spread out "dots". 
        
             
        
        
        
Answer: 60mph
Explanation:
Given the following :
First leg travel:
Distance = 30 miles 
Time of travel= 30 minutes = 0.5 hour
Second leg travel:
Distance = 60 miles 
Time of travel = one hour 
Average speed :
Speed = total Distance / time of travel 
Total distance in miles = (30 + 60) miles = 90 miles
Total time of travel = 1 hour + 0.5 hour = 1.5 hours
Average speed = total distance traveled / total travel time
Average speed = 90 miles / 1.5 hours
Average speed = 60 miles / hour
= 60mph
 
        
             
        
        
        
At the lowest point of its motion, kinetic energy is maximum and potential energy is minimum. This is where the velocity is a maximum. At the highest point of its motion, kinetic energy is minimum (i.e. zero) and potential energy is maximum.
 
        
                    
             
        
        
        
Answer:
   r2 = 1 m
therefore the electron that comes with velocity does not reach the origin, it stops when it reaches the position of the electron at x = 1m
Explanation:
For this exercise we must use conservation of energy
the electric potential energy is
           U =  
for the proton at x = -1 m
           U₁ = 
for the electron at x = 1 m
           U₂ =  
starting point.
         Em₀ = K + U₁ + U₂
         Em₀ =  
final point
          Em_f =  
    
energy is conserved
         Em₀ = Em_f
         \frac{1}{2} m v^2 - k \frac{e^2}{r+1} + k \frac{e^2}{r-1} = k e^2 (- \frac{1}{r_2 +1} + \frac{1}{r_2 -1})              
        
         \frac{1}{2} m v^2 - k \frac{e^2}{r+1} + k \frac{e^2}{r-1} = k e²(   )
 )
we substitute the values
 ½ 9.1 10⁻³¹ 450 + 9 10⁹ (1.6 10⁻¹⁹)² [  ) = 9 109 (1.6 10-19) ²(
 ) = 9 109 (1.6 10-19) ²(  )
 )
           2.0475 10⁻²⁸ + 2.304 10⁻³⁷ (5.0125 10⁻³) = 4.608 10⁻³⁷ (  )
 )
           2.0475 10⁻²⁸ + 1.1549 10⁻³⁹ = 4.608 10⁻³⁷      
            
           r₂² -1 = (4.443 10⁸)⁻¹
            
           r2 =  
           r2 = 1 m
therefore the electron that comes with velocity does not reach the origin, it stops when it reaches the position of the electron at x = 1m
 
        
             
        
        
        
To solve this problem we will apply the concepts related to wavelength as the rate of change of the speed of the wave over the frequency. Mathematically this is

Here,
v = Wave velocity
f = Frequency,
Replacing with our values we have that,

\lambda = 0.68m 
The distance to move one speaker is half this

Therefore the minimum distance will be 0.34m