If you have lifted 10 pounds 2 feet, you have done foot-pounds of work.

If element x has 99 protons how many electrons does it have

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656(red) and 486 (blue). light from a hydrogen lamp illuminates a diffraction grating with 500 lines per mm, and the light is observed on a screen 1.50 behind the grating. what is the distance between the first-order red and blue fringes?

If frequency goes down, what happens to wavelength? does it get shorter or longer?