Question

Consider a particle whose wavefunction at some fixed time t is represented by
-A if -2≤x≤0
ψ(x)= A if 0≤x≤3
0 otherwise
(a) What is the normalization constant A?

(b) What is the probability of finding the particle at a position x≤0?

(c) What is the expected value of position x?

(d) What is the expected value of momentum p?

Answer 1

|psi(x)|^2 integrated from minus to plus infinity is 5 |A|^2, this has to be equal to 1, therefore you can choose A as 1/sqrt(5) (you are free to multiply this by any phase factor
exp(i theta)).
The probability of the aprticle being at negative x is the integral from minus infinity to zero of |psi(x)|^2 dx, which is 2/5.

Expacted position: Integrate

x |psi(x)|^2 dx from minus to plus infinity, you get <x> = 1/2.

Answer 2

And, of course <p> = 0, because the fact that psi(x) is (or can be chosen to be a) real function of x, implies that the modulus squared of the momentum space wavefunction
psi(p) is an even function of p. To see this, note that:

psi(x) = 1/sqrt(2 pi hbar) Integral from minus to plus infinity of
dp psi(p) exp(i p x/hbar)

Take the complex conjugate of this:


psi*(x) = 1/sqrt(2 pi hbar) Integral from minus to plus infinity of
dp psi*(p) exp(-i p x/hbar) =

1/sqrt(2 pi hbar) Integral from minus to plus infinity of
dp psi*(-p) exp(i p x/hbar)

Since psi*(x) = psi(x), this means that

psi*(-p) = psi(p)

therefore

|psi(-p)|^2 = psi*(-p)psi(-p) =

psi(p)psi*(p) = |psi(p)|^2

Answer 3

Answers to q6 and 8 ?

Answer 4

Please q6 and q8 !

Answer 5

prob 3 C

Answer 6

3C is 3/2
6A is pi/2 and pi/4
6B is 1/2 and 1/2
Looking for 6C and 6D
8A is 1/2, 1/2, 0, 0
8B is 0, 0, 1/2, 1/2
8C is 1, 1, 0, 0
Looking for 8D and 8E
8F is No

Answer 7

Thank you.
And waiting for the rest answers

Answer 8

5 plz....

Answer 9

7a 1/2 7b 1/2

Answer 10

Problem 9 plzz

Answer 11

8D ,8E,6C,6D and 9

Answer 12

9 is 175.8


Anyone 8D ,8E,6C,6D?

Answer 13

6C,6D,8C,8D please..

Answer 14

4a,b,c,d plz ?

Answer 15

for 4 some one already gave you so you have:

4a: 1/sqrt(5)
4b 2/5
4c 1/2
4d 0

Answer 16

3a and b please

Answer 17

thx very much helper

Answer 18

5 plz?

Answer 19

5A i 0 0 -i 5b -i 0 0 i 5C -1 -1 -1
3a is 2nd option 3b is 2nd option
6C,6D,8C,8D please

Answer 20

8c = 1, 1, 0, 0
8D= 1/n,1/n,0,0,1/n,1/n,

Please 6C and 6D

Answer 21

JLG - Thanks for 8D and 8E. Didn't realize n was acceptable.
Anyone have 6C and 6D?
5 a) {{i,0}{0,-i}}
5 b) {-{i,0}{0,i}}
5 c) -1, -1, -1

Answer 22

6C and 6D

Answer 23

6c: 1/2+1/(2*sqrt(2)
1/2-1/(2*sqrt(2)
6D I continius lost..

Answer 24

6D is the same that 6 C :)

Answer 25

thx all, 8e please

Answer 26

8e: 0,1/n, 1/n

Answer 27

Thanks JLG

Answer 28

THANKS

Answer 29

THANKS ANNE

Answer 30

6c second part ans. is not accepted,,,wat is its numerical value.

Answer 31

Hey Guys... Ready for the final??

Answer 32

Helloo Any answer for the Final?

Answer 33

1] Given qubit 1 in the state 35|0>+45|1> and qubit 2 in the state 12√|0>+i2√|1>, what is the state of the composite system?
in form of a│00> + b│01> + c│10> + d│11>
find a b c d.

2] Which of the following states is entangled?
a) |++>
b) 45|01>−35|11>]
c) 1/√3|01> +1/√3|10>−1/3|11>
d) 1+i/√22|++> − 1+i/√22|+−>
+ 1−i/√22|−+> − 1−i/√22|−−>