If the kinetic energy of a particle is increased to $4$ times its initial value,how many times will the associated de Broglie wavelength become?

The kinetic energy (in $J$) of a particle of mass $4.5 \times 10^{-31} \ kg$ having a wavelength of $1000 \ nm$ is : $(h = 6.62 \times 10^{-34} \ J \ s)$

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

If the radius of the first orbit of the $H$ atom is $a_0$, then the de Broglie wavelength of the electron in the third orbit will be ....... (in $\pi a_0$)

Which of the following relations is correct,if the wavelength $(\lambda)$ is equal to the distance travelled by the electron in one second? $h$ is the Planck's constant and $m$ is the mass of electron.

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