Flashes are in constant motion
 
        
             
        
        
        
Answer:
This question is incomplete
Explanation:
This question is incomplete because of the absence of the time taken to complete one full cycle.
Frequency (<em>f</em>) will be calculated first as 
<em>f </em>= <em>N </em>÷<em> t</em>
where <em>N </em>is the number of cycles and <em>t </em>is the time taken to complete one full cycle. The unit for frequency is Hertz (Hz).
To calculate the period, <em>T, </em>the formula below will be used 
<em>T </em>= 1 ÷ <em>f</em>
The unit for period is secs
 
        
             
        
        
        
... cloak of invisibility spread over it.
        
                    
             
        
        
        
<h2>
Answer:</h2>
Time
<h2>
Explanation:</h2>
The average speed of an object that is moving is defined as the distance traveled  divided by the time of travel. You can measure the distance with a ruler and the time with a stopwatch. This can be expressed as the following formula:

For instance, if an object travels a distance  in 4 seconds, the the average speed is:
 in 4 seconds, the the average speed is:

 
        
        
        
Aerobie.  Frisbee.  Discus.  Javelin.  I suppose an American football to some extent. 
<span>Pull!  Clay pigeons.  Arrows.  Wingsuit.  Kites.  Hang gliders.  Sails.  sailboat keels/dagger boards.  Water skis.  Ski jumping skis.  Boomerang.  </span>
<span>I'm excluding spheres and parachutes as bluff bodies even though aerodynamics often plays a big part in their motion.</span>