A 0.057 kg tennis ball and a tennis racket collide. The racket has an initial momentum of -2.80 kg-m/s and a final momentum of -1.97 kg-m/s. The ball
has an initial momentum of 0.02565 kg-m/s. If you assume the collision is
elastic, what is the final velocity of the ball?
A. -83.26 m/s
B. -4.75 m/s
O c.-14.11 m/s
OD. -0.80 m/s

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?