solution:
We know v0 = 0, a = 9.8, t = 4.0. We need to solve for v
 so,
 we use the equation:
v = v0 + at
v = 0 + 9.8*4.0
v = 39.2 m/s
Now we just need to solve for d, so we use the equation:
d = v0t + 1/2*a*t^2
d = 0*4.0 + 1/2*9.8*4.0^2
d = 78.4 m
 
        
             
        
        
        
The best name for the ionic bond that forms between them is Beryllium Bromide.
We have been provided with data,
Beryllium charge, q = 2
Bromine charge, q = -1
As we know the valance electron of Be is +2  and the valance electron of bromine is -1. Since one is metallic and the other is non-metallic. 
Now, when they combine they exchange valance electron, and bromine change into bromide so they form Beryllium Bromide.
So, the best name for the ionic bond that forms between them is Beryllium Bromide.  
Learn more about ionic bonds here:
brainly.com/question/21464719
#SPJ4
 
        
             
        
        
        
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)
        
                    
             
        
        
        
Most likely the atoms of that elements are compress. :)