A disc is free to rotate in a horizontal plane about an axis through its centre o. A small object p is placed on the disc so that op=0.2m. Contact between the particle and the disc is rough and the coefficient of friction is 0.5. the disc then begins to rotate Find the angular velocity of the disc when the particle is about to slip

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656 nm(red) and 486 nm (blue). light from a hydrogen lamp illuminates a diffraction grating with 520lines/mm , and the light is observed on a screen 1.5m behind the grating. part a what is the distance between the first-order red and blue fringes? express your answer to two significant figures and include the appropriate units.

What type of light does this light bulb produce most (i.e. at what wavelength does the spectrum have maximum intensity)?

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.