Answer:

Explanation:
First, denote our known values;

Mass is impulse divided by change in velocity:

Hence, the mass of the ball is 141.30grams
 
        
             
        
        
        
3, protons are positive and there are 3 positive atoms visible
        
             
        
        
        
Answer:
a . 0.35cm
b.  11.33cm
Explanation:
a. Given both currents are in the same direction, the null point lies in between them. Let x be distance of N from first wire, then distance from 2nd wire is 4-x
#For the magnetic fields to be zero,the fields of both wires should be equal and opposite.They are only opposite in between the wires:

Hence, for currents in same direction, the point is 0.35cm
b. Given both currents flow in opposite directions, the null point lies on the other side. 
#For the magnetic fields to be zero,the fields of both wires should be equal and opposite.They are only opposite in outside the wires:
 Let x be distance of N from first wire, then distance from 2nd wire is 4+x:

Hence, if currents are in opposite directions the point on x-axis is 11.33cm