net force= the sum of all the forces acting on the object
the frictional force is opposite to the direction of motion of the object
If the object moves to the right (positive) then the friction force moves to the left (negative).
so the net force: 50 N - 5 N = 45 N (B)
She does 200J .
We know she uses 20N of force and 10m is the distance. We multiply both numbers and we are given our answer of 200J. Hope this was helpful. :)
Answer:
0.099C
Explanation:
First, we need to get the common potential voltage using the formula

Where V is the common voltage, C and V represent capacitance and charge respectively. Subscripts 1 and 2 to represent the the first and second respectively. Substituting the above with the following given values then

Therefore

Charge, Q is given by CV hence for the first capacitor charge will be 
Here, 