Normalization factor in wave equation

In summary, the conversation discusses a calculus question involving an integral with limits of integration from a to 0. The integral is simplified to 1 = A^2 a/2, but the second term is incorrect due to the placement of the 4 in the sine function. After correcting the integral, the value is now correct.
  • #1
hnicholls
49
1
(Note: although arising in QM, this is essentially a calculus question)

Ѱ (x) = A sin (n╥x/a)

1 = ∫ l Ѱ (x) l^2 dx with limits of integration a to 0

1 = ∫ A^2 sin^2 (n╥x/a) dx with limits of integration a to 0

Indefinite integral ∫ sin^2 x dx = x/2 - sin2x/4

I know this integral should reduce to 1 = A^2 a/2

But what I get is

I = A^2 [a/2 - sin (2n╥a/4a) - 0/2 - sin (2n╥0/4a)]

Third and fourth term within bracket are 0, but second term is 1

i.e., sin (n╥/2) = 1

I assume I'm missing something, but not sure what it is.

Thanks
 
Physics news on Phys.org
  • #2
Your integral is not right. In the second term, the 4 is not inside the argument of the sine function:

[tex]\int A^2 \sin^2(x) dx = \frac{x}{2}-\frac{\sin(2x)}{4} + C[/tex]
 
  • #3
Thanks.

That was my problem.

Correct value now.
 

Related to Normalization factor in wave equation

What is the normalization factor in the wave equation?

The normalization factor in the wave equation is a constant that is used to ensure that the total energy of the system remains constant over time. It is typically denoted as A in the equation.

Why is the normalization factor important in the wave equation?

The normalization factor is important because it helps to maintain the physical significance of the wave equation. It ensures that the amplitude of the wave remains constant and does not increase or decrease over time, which is necessary for accurate mathematical modeling of physical systems.

How is the normalization factor determined in the wave equation?

The normalization factor is determined by considering the initial conditions of the system. It is chosen such that the total energy of the system is equal to the initial energy at all times. This allows for a consistent and accurate representation of the physical system.

Can the normalization factor change over time in the wave equation?

No, the normalization factor remains constant over time. It is chosen at the beginning of the system and does not change, as it is meant to maintain the total energy of the system.

Are there different methods for determining the normalization factor in the wave equation?

Yes, there are different methods for determining the normalization factor. Some methods involve using physical principles, while others involve mathematical techniques, such as the method of separation of variables. The choice of method depends on the specific system being modeled and the desired accuracy.

Similar threads

Replies
2
Views
591
  • Quantum Physics
Replies
20
Views
1K
  • Quantum Physics
Replies
13
Views
794
Replies
1
Views
646
  • Quantum Physics
Replies
1
Views
327
  • Quantum Physics
Replies
17
Views
854
Replies
10
Views
1K
  • Quantum Physics
Replies
31
Views
3K
Replies
4
Views
1K
Replies
2
Views
719
Back
Top