How to plot a function with several constants using Wolfram Mathematica

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To plot the probability density function ψ*ψ = A^2 (x^2)exp(-2a(mx^2/h) in Wolfram Mathematica while keeping the constants m, a, A, and h, one must recognize that Mathematica treats these constants as variables. Substituting specific values for the constants allows for graphing, but this does not guarantee the expected graph. A suggested approach is to normalize the wave function to eliminate one constant and derive a characteristic length scale, α = √(ħ/ma), which simplifies the function. Changing variables from x to x/α can help remove the constants, enabling a clearer plot. Using the Manipulate function in Mathematica can also facilitate exploring the effects of varying constants on the graph.
Hany_Draidi
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How can I plot this probability density function using Wolfram Mathematica Keeping the constants the same.
ψ*ψ= A^2 (x^2)exp(-2a(mx^2/h)) ; where m,a,A,and h are constants and I want the graph in terms of them.
I tried: Plot[A^2 *(x^2)*exp(-2a(mx^2/h)),{x,-1000,1000}]
 
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You can't.
 
Hany_Draidi said:
How can I plot this probability density function using Wolfram Mathematica Keeping the constants the same.



ψ*ψ= A^2 (x^2)exp(-2a(mx^2/h)) ; where m,a,A,and h are constants and I want the graph in terms of them.



I tried: Plot[A^2 *(x^2)*exp(-2a(mx^2/h)),{x,-1000,1000}]

I would say you can't do that since Wolfram Alpha assumes that these terms are variables. Hence, there is no approach for this. You could just substitute the constants with any values and then, check the graph. You just have a graph; that doesn't guaranteed the exact graph you should expect. You will need to substitute random values!

I may be wrong. I am just assuming that is true.
 
You should be able to solve for A in terms of a, m, and h by requiring the wave function be normalized. That'll get rid of one constant.

What you want to do is come up with some combination of the constants that is a characteristic length in the problem. In this case, your wave function is
$$\psi(x) = A x e^{-\frac{ma}{\hbar}x^2}.$$ The argument of the exponential has to be unitless, and if you check the units, you'll indeed find that the combination ##ma/\hbar## has units of 1/length2. A natural choice for your length scale would therefore be ##\alpha=\sqrt{\hbar/ma}##. Now if you change variables from ##x## to ##x/\alpha##, you'll find that all of the constants will be gone. Once you have the density in that form, you can plot it using Mathematica.
 
Try using Manipulate. You can set the constants to starting values and then vary them with the sliders to see what effect they have. A notebook is attached
 

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Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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