In the Bohr orbits if the mass of electron is halved, the radius will become x times of original, keeping velocity constant. What is the value of x ?

If the radius of the first Bohr orbit is r, what would be the radius of the second ?

Keeping the mass constant , if the radius of the earth is halved, then the span of a day

Keeping the mass fixed , if the radius of the earth is halved, the acceleration due to gravity at any place will be

If the radius of earth is halved and the mass is same then what will be the change of its acceleration due to gravity.

What is the velocity of electrons in'the first Bohr Orbit of Hydrogen atom:

The weight of a body on the earth's surface is W. if the radius of the earth becomes double keeping its mass unchanged, what will be the weight of the body ?

What is the energy in joules, requried to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Borh orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is -2.18xx10^(-11) erg.

What will be the value of 5x xx 2x^2y xx 2y