Posted by Jacob on .
What would be the uncertainty in velocity (miles/hr) of a neutron beam particle if the position can be measured within +/ 25 angstroms.
The rest mass of a neutron = 1.67493 X 10^27 kg or 1.008664904(14) amu.
I know you have to use the heisenberg uncertainty principle: (deltaX)(delta mv) > (or equal to) planck's constant/4pi.
So far I have (+/ 25 A)(1.67493XX 10^27 kg) > 5.21X10^34
what do i do now?

CHEMISTRY 
DrBob222,
I believe you must convert Angstroms to meters.
h = 6.626 x 10^34 J.s instead of the 5.21 you have. Then solve the equation and convert m/s you get for the answer to mi/hr 
CHEMISTRY 
DrBob222,
Also, consider that the uncertainty is +/ 25 and the total "swing" is 50 A^{o}.Check my thinking.