The radius, r, of the child from the center of the wheel is
r = 1.3 m
The wheel makes one revolution in 4.2 s. Its angular velocity is
ω = (2π rad)/(4.2 s) = 1.496 rad/s
The linear speed of the child is the tangential velocity, given by
v = rω
   = (1.3 m)*(1.496 rad/s)
   = 1.945 m/s
Answer: 1.95 m/s  (nearest hundredth)
        
                    
             
        
        
        
To develop this problem it will be necessary to apply the concepts related to the frequency of a spring mass system, for which it is necessary that its mathematical function is described as

Here,
k = Spring constant
m = Mass 
Our values are given as,


Rearranging to find the spring constant we have that,




Therefore the spring constant is 1.38N/m
 
        
             
        
        
        
I would say that insofar as the two stars temperatures are presumably closely related to their luminosity, that the blue star at 156,100 k compared to 3000k for the red star then the blue star has a luminosity of 52 times that of the red star.
        
             
        
        
        
When crest of one wave interferes with the trough of other wave, the amplitude of the resultant wave formed is less. Hence the type of interference is destructive interference.