Question

At the surface of Venus the average temperature is a balmy 460∘C due to the greenhouse effect (global warming!), the pressure is 92 Earth-atmospheres, and the acceleration due to gravity is 0.894 gEarth. The atmosphere is nearly all CO2 (molar mass 44.0g/mol) and the temperature remains remarkably constant. We shall assume that the temperature does not change at all with altitude. a. What is the atmospheric pressure 5.00 km above the surface of Venus? Express the answer in Earth--atmospheres. b. What is the atmospheric pressure 5.00 km above the surface of Venus? Express the answer in Venus-atmospheres. c. What is the root-mean-square speed of the CO2 molecules at the surface of Venus and at an altitude of 5.00 km? Express the answer in meters per second.

Answer 1

(1) Given Data:

At the surface of venus:

Temperature T = 460 C = 733 K;

Pressure Po = 92 x earth atmopheric pressure

find earth atmopheric pressure in terms of venus atmospheric pressure;

earth atmopheric pressure = Po/92 = venus atmospheric prressure/92

Acceleration due to gravity g' = 0.894 x (g of Earth) = 0.894 x 9.81 = 8.77 m/s^2;

Molar mass of , M = 44 g/mol = 0.044 kg/mol;

Solution:

(a) find atmospheric pressure 5.00 km (i.e altitude, h = 5000 m) above the surface of Venus;

relation for pressure variation as a function of altitude h is given as;

(b) atmospheric pressure 5.00 km (i.e altitude, h = 5000 m) above the surface of Venus in venus atmosphere;

(c) rms speed of CO2;