The average speed is 52km
Explanation:
Given that,
Capacitor 
Resistor 
Peak voltage = 5.10 V
(A). We need to calculate the crossover frequency
Using formula of frequency

Where, R = resistor
C = capacitor
Put the value into the formula


(B). We need to calculate the
when 
Using formula of 

Put the value into the formula


(C). We need to calculate the
when 
Using formula of 


(D). We need to calculate the
when 
Using formula of 


Hence, This is the required solution.
The centripetal acceleration is given by

where v is the tangential speed and r the radius of the circular orbit.
For the car in this problem,

and r=40 m, so we can re-arrange the previous equation to find the velocity of the car: