Answer:
3a, 2b,4c,1d
Explanation:
what do I need to explain just something you know 
 
        
             
        
        
        
Answer:
distance r from the uranium atom is 18.27 nm
Explanation:
given data 
uranium and iron atom distance R = 44.10 nm
uranium atom = singly ionized
iron atom = doubly ionized
to find out
distance r from the uranium atom
solution
we consider here that uranium electron at distance = r
and electron between uranium and iron so here 
so we can say electron and iron  distance = ( 44.10 - r ) nm
and we know single ionized uranium charge q2= 1.602 ×  C
 C
and charge on iron will be q3 = 2 × 1.602 ×  C
 C
so charge on electron is q1 =  - 1.602 ×  C
 C
and we know F =  
   
so now by equilibrium 
Fu = Fi
 =
  =   
 
put here k =  and find r
 and find r 
 =
  =   
 

r = 18.27 nm
distance r from the uranium atom is 18.27 nm
 
        
             
        
        
        
Acceleration = (change in speed) / (time for the change)
Acceleration = (4 m/s) / (8 seconds)
Acceleration = 0.5 m/s²
Force = (mass) x (acceleration)
Force = (85 kg) x (0.5 m/s²)
Force = 42.5 Newtons
        
                    
             
        
        
        
Answer:
A. The starting height of the ball
Explanation:
When we talk about controlled variables, we refer to the variable that should be kept the same throughout the experiment. The reason why we do this, is to limit anything else that is not being tested, that may affect the results of the experiment.
In the scenario given, the experiment is to see the relationship between the <u>initial height of a basketball</u> and the <u>height of its rebound bounce. </u>
So you the starting height of the ball should vary, meaning it is NOT controlled.