Answer:
Number of electrons, 
Explanation:
It is given that,
Charge, q = 4.33 C
We need to find the number of electrons that make 4.33 C of charge. According to quantization of charge as :

n = number of electrons
e = electron's charge



So, the number of electrons are
Hence, this is the required solution.
Answer:
(e)
Explanation:
At resonance we know that 
That is 



We have given resonance frequency f =4511 Hz and inductance L=1.82 mH
So 



So option e is the correct answer
Answer:
D. 5.7 m
Explanation:
The acceleration of the car is -8.7 m/s² and the car has an initial speed (u) of 10 m/s. The car said to come to rest, that means that the final velocity (v) of the car is 0 m/s.
To find the distance traveled by the car (s) before complete stop, this equation is being used:
v² = u² + 2as

The car traveled 5.7 m before coming to a complete stop
For a cylinder that has both ends open resonant frequency is given by the following formula:

Where n is the resonance node, v is the speed of sound in air and L is the length of a cylinder.
The fundamental frequency is simply the lowest resonant frequency.
We find it by plugging in n=1:

To find what harmonic has to be excited so that it resonates at f>20Hz we simply plug in f=20 Hz and find our n:

We can see that any resonant frequency is simply a multiple of a base frequency.
Let us find which harmonic resonates with the frequency 20 Hz:

Since n has to be an integer, final answer would be 323.