How did the current change when the circuit was initially closed in Part 2 of this exercise? Explain your answer by referencing Panel 1 and the definitions of a capacitor and of current.

4.18

Explanation:

Givens  

The car's initial velocity  = 0 and covering a distance Δx = 1/4 mi = 402.336 m in a time interval t = 4.43 s.  

Knowns

We know that the maximum static friction force is given by:

μ_s*n                         (1)

Where μ_s is the coefficient of static friction and n is the normal force.  

Calculations  

(a) First, we calculate the acceleration needed to achieve this goal by substituting the given values into a proper kinematic equation as follows:

Δx=

a=41 m/s

This is the acceleration provided by the engine. Applying Newton's second law on the car, so in equilibrium, when the car is about to move, we find that:  

Substituting (3) into (1), we get:

μ_s*m*g

Equating this equation with (4), we get:

ma=  μ_s*m*g

 μ_s=a/g

      =4.18