Question

2. An aluminum scuba tank, which has an internal volume of 11.1 L, is filled with air to a pressure of 3000 psi when at room temperature (i.e. 20.0 OC). A diver takes the tank into seawater, where the water temperature is 46 degrees Fahrenheit (i.e. 8.00OC). To what pressure does the air in the tank drop? (The thermal coefficient of expansion for aluminum is 24.0x10-6 OC -1 .)

Answer: 2880 psi

Don't need #2, just #3 please.

3. For the air in the scuba tank in Problem 2, find:

(a) the rms speed of the oxygen molecules at room temperature;

(b) the rms speed of the nitrogen molecules at room temperature;

(c) the rms speed of the oxygen molecules at the colder temperature;

(d) the rms speed of the nitrogen molecules at the colder temperature;

(e) the total translational kinetic energy of the air molecules in the scuba tank.

(Note: the molar masses of nitrogen and oxygen gas are 28.0 g/mol and 32.0 g/mol, respectively.)

Answers: a) 478 m/s; b) 511 m/s; c) 468 m/s; d) 500 m/s; e) 330 kJ

Answer 1