00:01
Estimate the minimum uncertainty in the momentum.
00:03
We can use the principle of uncertainty, delta x, delta p, greater than or equal to h over 4 pi.
00:12
So delta p is greater than or equal to h over 4 pi delta x.
00:18
So we plug in 6 .6 times 10 to the negative 34 divided by 4 pi times 5 times 10 to the negative 15, and our delta p is greater than or equal to 1 .05 times 10 to the negative 20 kilogram meters per second.
00:38
It should be kilogram meters per second.
00:42
For b, we'd like to find, to estimate, we want to obtain the kinetic energy of an electron.
00:54
So our magnitude of momentum, delta p .c, is equal to 3 .15 times 10 to the net, negative 12 joules or 19 .9 mev.
01:10
Now we can use a relativistic equation.
01:13
E squared is pc squared plus m not c squared or 19 .9 squared plus 0 .11 squared which is equal to um then if we take the square root then we want to take the square root of this to find e.
01:36
So we should we find e is 19 .9 m .e .v.
01:42
And we know our total energy is our kinetic plus m0c squared.
01:47
So our kinetic energy is 19 .4 m .e .v.
01:54
For part c, we'd like to find the magnitude of the potential energy...