-- In combination with 610 Hz, the beat frequency is 4 Hz.
So the unknown frequency is either (610+4) = 614 Hz 
or else (610-4) = 606 Hz.
In combination with 605 Hz, the beat frequency will be 
either (614-605) = 9 Hz or else (606-605) = 1 Hz.
-- In actuality, when combined with the 605 Hz, the beat 
frequency is too high to count accurately.  That must be 
the 9 Hz rather than the 1 Hz.
So the unknown is (605+9) = 614 Hz.
  
        
             
        
        
        
Answer:This is an explanation
 for 150 km its all ik i tried hard ty
Explanation:The car covers 150 km in 3 hours or 3*60 = 180 minutes.
So in 12 min the car will cover (12/180)*150 = 10 km.
 
        
                    
             
        
        
        
Answer:

Explanation:
The volume charge density is defined by ρ =  (Equation A), where Q is the charge and V, the volume.
 (Equation A), where Q is the charge and V, the volume.
The units in the S.I. are  , so we have to express the radius in meters:
, so we have to express the radius in meters:
inner radius = 
outer radius = 
Now, we know that the volume of the sphere is calculated by the formula:
 , and as we have an spherical shell, the volume is calculated by the difference between the outher and inner spheres:
, and as we have an spherical shell, the volume is calculated by the difference between the outher and inner spheres:
V =  , where
, where  is the outer radius and
 is the outer radius and  is the inner radius.
 is the inner radius.
Replacing the volume formula in the Equation A:
ρ = 
ρ = 
Replacing the values of the outer and inner radius whe have:
ρ = 
ρ = 
 
        
             
        
        
        
The frequency of any wave is  (wave speed) / (wavelength) .
The speed of light is  3 x 10⁸ m/s.
If the wavelength is 10 nm (10⁻⁸ m) , then the frequency is
                         (3 x 10⁸) / (10⁻⁸)  =  <em>3 x 10¹⁶ Hz</em>
That's 30 million gigahertz !