If the velocity of a hydrogen molecule is $5 \times 10^4 \, cm \, sec^{-1}$,then its de-Broglie wavelength is ............. $\mathring{A}$.

Calculate the wavelength in nanometers associated with a particle moving with a velocity of $1.0 \times 10^3 \, m s^{-1}$. (Given: mass $m = 1.67 \times 10^{-27} \, kg$ and Planck's constant $h = 6.63 \times 10^{-34} \, J s$)

Dual behavior of matter proposed by de Broglie led to the discovery of electron microscope, often used for the highly magnified images of biological molecules and other types of material. If the velocity of the electron in this microscope is $1.6 \times 10^{6} \,ms^{-1}$, calculate the de Broglie wavelength associated with this electron.

The de-Broglie wavelength of a tennis ball of mass $60 \, g$ moving with a velocity of $10 \, m/s$ is approximately

Two particles $A$ and $B$ are in motion. If the wavelength associated with particle $A$ is $5 \times 10^{-8} \ m$,calculate the wavelength (in $\mathring{A}$) associated with particle $B$ if its momentum is half of $A$.

Calculate the mass of a photon,if its wavelength is given as $0.35 \ nm$.