Ten and one-half foot-pounds of work is required to compress a spring 3 inches from its natural length. find the work required to compress the spring an additional one-half inch. (round your answer to two decimal places.)

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?