If the kinetic energy of a particle is reduced to half,the de-Broglie wavelength becomes

If the kinetic energy of an electron is increased four times,the wavelength of the de-Broglie wave associated with it would become

The mass of a particle is $1 \, mg$ and its velocity is $4.5 \times 10^5 \, cm/s$. What will be the wavelength of this particle? $(h = 6.652 \times 10^{-27} \, erg \cdot s)$.

In a hydrogen atom,the de Broglie wavelength of an electron in the second Bohr orbit is: [Given that Bohr radius,$a_0 = 52.9 \; pm$]

$A$ $200 \ g$ golf ball is moving with a speed of $5 \ m$ per hour. The associated wavelength is $(h = 6.625 \times 10^{-34} \ J \ s)$.

If the kinetic energy of an electron of mass $9.0 \times 10^{-31} \ kg$ is $8.0 \times 10^{-25} \ J$,the wavelength of this electron in $nm$ is