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a) Compute x,p,x2,p2, for the states 0and 1, by explicit integration. Comment; In this and other problems involving the harmonic oscillator it simplifies matters if you introduce the variable mxand the constant (m)1/4.

b) Check the uncertainty principle for these states.

c) Compute T(the average kinetic energy) and V(the average potential energy) for these states. (No new integration allowed). Is their sum what you would expect?

Short Answer

Expert verified

Answer

(a) The value of is x||2dx-0and the value of pis

mdx/dt=0and the value of x2is 32mand the value of P2is 3m2.

(b)The uncertainty principal for these states is greater than2

(c) The value of the average kinetic energy is 14(n=0)34(n=1)and the average potential energy is 14(n=0)34(n=1).The sum of these two is same as expected value.

Step by step solution

01

- Define explicit integration

In this method, the accelerations and velocities at a specific time point are taken to be constant during a time interval and are utilised to find the location of the following time point.

02

- The value of x and P

(a)

The function 0is even, and 1is odd. In either case 2is even, so the value of x=x||2dx=0. Thereforep=mdxdt=0

Thus, the value of xis x||2dx-0and the value of pismdxdt=0

Now, evaluate the value of x2and p2.

The below values are known that

0=e-2/2

1=2e-2/2

For n=0, the value of x2will be

x2=2-x2e-2/2dx ....................(1)

For given equation-

=mxx=mx2=2m

And

x=mdx=dm

Substitute the value of x2and dxin equation (1)

x2=2-2me-2dmx2=2m3/2-2e-2d=1m2=2m

And the value of P2is

P2=0didx20dx=22m-e-2d2d2e-2d=-m2-=m2

For n=1, the value of x2will be

x2=22-x22e-2dx

Substitute the value of and in the above equation. So,

x2=22m3/2-4e-2d=32m4=32m

And the value of P2is

P2=-222m-e-2/2d2d2e-2/2d=-2m34-32=3m2

Therefore, the value of x2is 32mand P2is 3m2

03

- The uncertainty principal of above states

(b)

The value of will be for :

x=x2-x2=2mP=P2-P2=m2

xP=2mm2=2

(Right t the uncertainty moment)

For n=1, the value will be :

x=32mP=3m2xP=32>2

The uncertainty principal for these states is greater than2

04

- The value of the average kinetic energy and the average potential energy.

(c)

The average kinetic energy is:

T=12mP2

=14(n=0)34(n=1)

The average potential energy is

V=12m2x2

=14(n=0)34(n=1)

T+V=H=12(n=0)=E032(n=1)=E1, as expected.

So, the value of the average kinetic energy is 14(n=0)34(n=1)and the average potential energy is 14(n=0)34(n=1). The sum of these two is same as expected value.

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