Question

(1) The atmospheric pressure P in pounds per square inch (psi) is given by

P = 14.7 e^{?0.21 a}

where a is the altitude above sea level (in miles). If a city has an atmospheric pressure of 11.31 psi, what is its altitude? (Recall that 1 mi = 5,280 ft. Round your answer to the nearest foot.)
ft

(2) An artifact was found and tested for its carbon-14 content. If 83% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.)
yr

(3) A seismograph 300 km from the epicenter of an earthquake recorded a maximum amplitude of

4.1 10²