The resonant frequency of a circuit is the frequency
at which the equivalent impedance of a circuit is purely real (the imaginary part is null).
Mathematically this frequency is described as

Where
L = Inductance
C = Capacitance
Our values are given as


Replacing we have,



From this relationship we can also appreciate that the resonance frequency infers the maximum related transfer in the system and that therefore given an input a maximum output is obtained.
For this particular case, the smaller the capacitance and inductance values, the higher the frequency obtained is likely to be.
Answer:

Explanation:
From the attached file diagram, the total force acting on the charged box is the downward weight and the repulsive force acting in opposite to the weight force . Hence we can write the total force as

When fixed,F=o
Hence

The value of the acceleration is 16.2m/s^2
Answer:
W = 14.8 kJ
Explanation:
W = F S cos ∅
W = 4113 x 3.99 x cos 25.5
W = 16410.87 x 0.9025 = 14810.8 J or 14.8 kJ
Given that,
Mass of each washer = 4.9 g
We need to calculate the mass of two washers in kg
Using conversion of unit
Mass of each washer 
So, Mass of two washers is

Put the value of m


If 4 washer are attached to the spring
We need to calculate the applied force on the car
Using formula of force

Put the value into the formula


Hence, (i), The mass of two washers is 0.0098 kg.
(ii). The applied force on the car is 0.192 N.
Answer:
128805.2988 cm squared or 128000 to 3 significant figures.
Explanation:
Area of a circle : pi times radius squared or 
pi times 4.1×10^4 cm = 41000 pi or 128805.2988