Question

Calculate de broglie wavelength of A neutron(mass=1.6×10^-27) moving with kinetic energy of 0.04 ev
answer is 14.6 A​

Answer 1

Answer : The de-broglie wavelength of a neutron is, $1.46A^o$

Explanation : Given,

Mass of neutron = $1.6\times 10^{-27}Kg$

Kinetic energy = $0.04eV=0.04\times 1.6\times 10^{-19}J$

conversion used : $1eV=1.6\times 10^{-19}J$

First we have to calculate the velocity of neutron.

Formula used : $K.E=\frac{1}{2}\times m\times v^2$

where,

K.E = kinetic energy

m = mass of neutron

v = velocity of neutron

Now put all the given values in this formula, we get

$0.04\times 1.6\times 10^{-19}J=\frac{1}{2}\times 1.6\times 10^{-27}Kg\times v^2$

$v=2.83\times 10^3$

Now we have to calculate the de-broglie wavelength of a neutron.

Formula used : $\lambda=\frac{h}{m\times v}$

where,

$\lambda$ = wavelength

h = Planck's constant = $6.626\times 10^{-34}Js$

m = mass

v = velocity

Now put all the given values in this formula, we get

$\lambda=\frac{6.626\times 10^{-34}Js}{1.6\times 10^{-27}Kg\times 2.83\times 10^3}=1.46\times 10^{-10}m=1.46A^o$

Therefore, the de-broglie wavelength of a neutron is, $1.46A^o$

Answer 2

Answer:

1.46A°

Explanation:

use formula wavelength=h/ mv.

we can calculate v from K.E=1/2mv^2