Answer:
mass of box 1 = 2.20 kg
mass of box 2 = 5.93 kg
Explanation:
Let the mass of box 1 and box 2 is respectively
and 
so we will have
Force applied on box 1 then acceleration



Now we know that contact force between them in above case is given as



now we have

It’s FF= μ•Fn
Ff stands for friction force
The weird symbol is your coefficient of friction which has no units
Fn stands for normal force
Answer:

Explanation:
The Coulomb's Law gives the force by the charges:

Let us denote the positon of the charge q on the y-axis as 'y'.
The force between 'Q' and'q' is

where Θ is the angle between
and x-axis.

whereas

Finally, the x-component of the net force is
