The de Broglie wavelength of a particle is $1000 \ nm$. What is its momentum? $(h = 6.6 \times 10^{-34} \ J \ s)$

$A$ proton and a $Li^{3+}$ nucleus are accelerated by the same potential. If $\lambda_{Li}$ and $\lambda_{P}$ denote the de Broglie wavelengths of $Li^{3+}$ and proton respectively,then the value of $\frac{\lambda_{Li}}{\lambda_{P}}$ is $x \times 10^{-1}$. The value of $x$ is ............
(Rounded off to the nearest integer)
(Mass of $Li^{3+} = 8.3 \times \text{mass of proton}$)

Calculate the velocity of an electron having a de Broglie wavelength of $58 \ nm$ and mass $9.1 \times 10^{-31} \ kg$. Given: $h = 6.63 \times 10^{-34} \ Js$.

The wavelength of a photon is $5200 \ \mathring{A}$. At what velocity will an electron have the same wavelength as this photon (in $m/s$)?

The wavelengths of electron waves in two orbits are in the ratio $3: 5$. The ratio of the kinetic energy of the electrons will be:

What is the mass of a particle with a wavelength of $3.313 \mathring{A}$ moving with a speed of $2.0 \times 10^8 \ m \ s^{-1}$?