Answer:

Explanation:
Let the charge on the ball bearing is q.
charge on glass bead, Q = 20 nC = 20 x 10^-9 C
Force between them, F = 0.018 N
Distance between them, d = 1 cm = 0.01 m
By use of Coulomb's law in electrostatics

By substituting the values


Thus, the charge on the ball bearing is 
Complete Question
The complete question is shown on the first uploaded image
Answer:
the value of 
Explanation:
From the question we are told that
The equation is (x + y = 40)
The first value of x is 
The second equation is (0.75x + 1.5y = 40)
So substituting 

=> 
Now substituting y and
into second equation

=> 
So 
Answer:
1.F = 256 N
2.a = 8 m/s/s
By looking at the given information, you know force, and an acceleration. Therefore you have enough information to use the first formula.
F = ma
256 N = m * 8 m/s/s
m = 256 N/8 m/s/s
m = 32 Kg