Average speed is defined as total distance moved in total interval of time
so it is given as

now here is we show distance by "d" and time by"t"
then we will have mathematical expression as follows

 
        
             
        
        
        
Answer:
Stellar black holes form when the center of a very massive star collapses in upon itself. 
 
        
                    
             
        
        
        
Answer:
a
  
b
   
Explanation:
From the question we are told that 
   The  wavelength is  
   The  number of antinodal planes of the electric field considered is n  =  5
The  width is mathematically represented as 
        
        
       
Generally the  frequency the errors was made is  mathematically represented as 
    
Here c is the speed of light with value  
       is the wavelength of the microwave has to be in order for there still to be five antinodal planes of the electric field along the width of the oven, which is mathematically represented as
 is the wavelength of the microwave has to be in order for there still to be five antinodal planes of the electric field along the width of the oven, which is mathematically represented as 
      
       
So 
    
     
     
        
 
        
             
        
        
        
<u>Answer:</u>
a) Height of cliff = 44.145 meter
b) 7.5 meter far from its base the diver hit the water.
<u>Explanation:</u>
  We have equation of motion ,  , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
, s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
Diver's vertical motion:
    Initial velocity = 0 m/s, acceleration = 9.8  , we need to calculate displacement when time is 3 seconds.
, we need to calculate displacement when time is 3 seconds.
   
  So height of cliff = 44.145 meter.
b) Diver's horizontal motion:
 Initial velocity = 2.5 m/s, acceleration = 0  , we need to calculate displacement when time is 3 seconds.
, we need to calculate displacement when time is 3 seconds.
 
 So 7.5 meter far from its base the diver hit the water.