Answer:
Coefficient of static friction will be equal to 0.642
Explanation:
We have given acceleration 
Acceleration due to gravity 
We have to find the coefficient of static friction between truck and a cabinet will
We know that acceleration is equal to
, here
is coefficient of static friction and g is acceleration due to gravity
So 
So coefficient of static friction will be equal to 0.642
Answer:
The correct answer is A
Explanation:
The question requires as well the attached image, so please see that below.
Coulomb's Law.
The electrical force can be understood by remembering Coulomb's Law, that describes the electrostatic force between two charged particles. If the particles have charges
and
, are separated by a distance r and are at rest relative to each other, then its electrostatic force magnitude on particle 1 due particle 2 is given by:

Thus if we decrease the distance by half we have

So we get

Replacing we get

We can then multiply both numerator and denominator by 4 to get

So we have

Thus if we decrease the distance by half we get four times the force.
Then we can replace the second condition

So we get

which give us

Thus doubling one of the charges doubles the force.
So the answer is A.
The answer to your question is 10.24