Answer:

Explanation:
We define our values according to the text,
R= Radius
 Velocity
Velocity 
 Strenght of the vortex filament
Strenght of the vortex filament
From this and in a vectorial way we express an elemental lenght of this filmaent as  . So,
. So,

Where  imply a vector acting perpendicular to both vectors.
 imply a vector acting perpendicular to both vectors.
Applying Biot-Savart law, we have,

Substituting the preoviusly equation obtained,



So we can express the velocity induced is,

 
        
             
        
        
        
Answer:
gravity
Explanation:
the Forest of gravity causes objects to fall toward the center of the Earth.
 
        
                    
             
        
        
        
Well, according to the octet rule, an atom is chemically stable when the outer energy level is filled with 8 electrons. Similar is the case with noble gases. They contain 8 electrons in the outermost shell and thus they are stable.
        
             
        
        
        
<em><u>Primary coil:</u></em><em><u /></em><u />
It is the part of electric circuit in which input voltage is applied,,and it induces current in neighbouring secondary coil...
<em><u>Secondary coil:</u></em><em><u /></em><u />
It is the coil in which current is induced by primary coil...
        
             
        
        
        
Answer:
1568 J
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 80 Kg
Distance (d) = 5 m
Coefficient of kinetic friction (μ) = 0.4
Workdone (Wd) =? 
Next, we shall determine the normal reaction. This can be obtained as follow:
Mass (m) = 80 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal reaction (N) =? 
N = mg
N = 80 × 9.8
N = 784 N
Next, we shall determine force of friction. This can be obtained as follow:
Coefficient of kinetic friction (μ) = 0.4
Normal reaction (N) = 784 N 
Force of friction (F) =? 
F = μN
F = 0.4 × 784
F = 313.6 N
Finally, we shall determine the work done. This can be obtained as follow:
Distance (d) = 5 m
Force of friction (F) = 313.6 N
Workdone (Wd) =? 
Wd = F × d 
Wd = 313.6 × 5
Wd = 1568 J
Thus, the workdone is 1568 J