United states currency is printed using intaglio presses that generate a printing pressure of 7.8 x 104 lb/in2. a $20 bill is 6.1 in. by 2.6 in. calculate the magnitude of the force (in pounds) that the printing press applies to one side of the bill.

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?