Milwaukee is 121 mi (air miles) due west of grand rapids. maria drives 255 mi in 4.75 h from grand rapids to milwaukee around lake michigan. find
a. her average driving speed
b. her average travel velocity.

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?