It is right have a good day
explanation step by step
Quantum Theory is commonly related to Quantum Mechanics, or the physics of sub-atomic particles. Quantum Theory defines the theories or educated ideas behind Quantum Mechanics. I believe this is the answer you are looking for.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The workdone is 
Explanation:
From the question we are told that
The initial Volume is 
The final volume is 
The external pressure is
Generally the change in volume is

Substituting values we have


Generally workdone is mathematically represented as

W is negative because the working is done on the environment by the system which is indicated by volume increase
Substituting values


Now 
Therefore 

Answer:
a=4,32m/s^2
Explanation:
Fnet = F1 - F2
= 12-1.2
= 10.8N
m=2.5kg
Fnet =ma
10.8=2.5a then divide both sides by 2.5 to get acceleration
Answer:
f = 409 Hz
Explanation:
We have,
Length of the open organ pipe, l = 0.29 m
Frequency of vibration of second overtone, 
It is required to find the fundamental frequency of the pipe. For the open organ pipe, the frequency of second overtone is given by :

v is speed of sound
Let f is the fundamental frequency. It is given by :

The relation between f and f₂ can be written as :

So, the fundamental frequency of the pipe is 409 Hz.