13. a ground state hydrogen atom absorbs a photon of wavelength 94.98 nm and its electron attains a higher energy level. the atom then emits two photons: one of wavelength 4052.3 nm to reach an intermediate level and a second to return to the ground state. what was the wavelength of the second photon emitted?

During which of the following phases of the business cycle does the real gdp fall? a. trough b. expansion c. contraction d. peak

The market demand curve for a popular teen magazine is given by q = 80 - 10p where p is the magazine price in dollars per issue and q is the weekly magazine circulation in units of 10,000. if the circulation is 400,000 per week at the current price, what is the consumer surplus for a teen reader with maximum willingness to pay of $3 per issue?

Xinhong company is considering replacing one of its manufacturing machines. the machine has a book value of $39,000 and a remaining useful life of 5 years, at which time its salvage value will be zero. it has a current market value of $49,000. variable manufacturing costs are $33,300 per year for this machine. information on two alternative replacement machines follows. alternative a alternative b cost $ 115,000 $ 117,000 variable manufacturing costs per year 22,900 10,100 1. calculate the total change in net income if alternative a and b is adopted. 2. should xinhong keep or replace its manufacturing machine