The wavelength associated with the electron moving in the first orbit of hydrogen atom with velocity $2.2 \times 10^6 \ ms^{-1}$ (in $nm$) is $\left(m_e=9.0 \times 10^{-31} \ kg, h=6.6 \times 10^{-34} \ Js\right)$

An electron moves in an electric field with a kinetic energy of $2.5 \, eV$. The de Broglie wavelength associated with it is .....

If the wavelength is $5894 \, \mathring{A}$,the velocity of light is $3 \times 10^8 \, m/s$,and the value of $h$ is $6.6252 \times 10^{-34} \, kg \cdot m^2/s$,what will be the mass of a sodium photon?

The de Broglie wavelength associated with a ball of mass $1 \, kg$ having kinetic energy $0.5 \, J$ is

Two base balls (masses: $m_1 = 100 \ g$ and $m_2 = 50 \ g$) are thrown. Both of them move with uniform velocity,but the velocity of $m_2$ is $1.5$ times that of $m_1$. The ratio of de Broglie wavelengths $\lambda(m_1) : \lambda(m_2)$ is given by

The frequency of the de-Broglie wave of an electron in Bohr's first orbit of a hydrogen atom is . . . . . . . . . . $\times 10^{13} \ Hz$ (nearest integer).
[Given: $R_H$ (Rydberg constant) $= 2.18 \times 10^{-18} \ J$,$h$ (Planck's constant) $= 6.6 \times 10^{-34} \ J \cdot s$]