+2 electron charges = 2x1.6x10^-19Coulombs
 
        
             
        
        
        
When you rub inflated balloon with your hair or your kitten's fur, charge is induced on all over the balloon's surface. This is called "charging by friction" because you developed charges by rubbing to bodies with each other. It will also stick on your wall you can check it out. This is because of "unlike charges attract each other". Rubbed balloon and wall possessed unlike charges which made them stick together. 
        
             
        
        
        
Answer:
3125 N
Explanation:
diameter /2 =radius 
so r1 =14cm , r2 =35cm
f1/A1 =f2/A2.
f2 = f1 × A2 / A1
=500×1225 pi cm² / 96 pi cm²
f2 =3125N
 
        
             
        
        
        
Answer:
B = 7.6 T   direction of + x
Explanation:
For the proton beam to continue in the same direction the electric and magnetic forces must be equal
                = 0
 = 0
                = F_{e}
 = F_{e}
               Fm = q E
              
The electric force is in the direction of the electric field because it is the charge of the positive proton, the electric force goes in the direction of –y, therefore, the magnetic force cancels this force must go in the direction of + y
  The magnetic force is
              F_{m} = q v x B = q v B sin θ
              θ = 90
              B = q E / q v
              B = E / v
              B = 800/105
              B = 7.6 T
To find the direction of the magnetic field we use the right hand rule, the thumb goes in the direction of the proton velocity, the fingers extended in the direction of the magnetic field and the palm is the direction of force, for a positive charge.
 Thumb goes in the direction of the + z axis
Palm in the direction of +y
Fingers point in the direction of + x
 
        
             
        
        
        
Answer:
The magnitude of the force required to bring the mass to rest is 15 N.
Explanation:
Given;
mass, m = 3 .00 kg
initial speed of the mass, u = 25 m/s
distance traveled by the mass, d = 62.5 m
The acceleration of the mass is given as;
v² = u² + 2ad
at the maximum distance of 62.5 m, the final velocity of the mass = 0
0 = u² + 2ad
-2ad = u²
-a = u²/2d
-a = (25)² / (2 x 62.5)
-a = 5
a = -5 m/s²
the magnitude of the acceleration = 5 m/s²
Apply Newton's second law of motion;
F = ma
F = 3 x 5
F = 15 N
Therefore, the magnitude of the force required to bring the mass to rest is 15 N.