Molecular Physics | Thermodynamics Answers

For a certain gas, R = 0.277 kJ/kg-K and k = 1.384. a) What are the value of cp

and cv? b) What mass of this gas will occupy a volume of 0.425 m3 at 517.11

kPaa and 26.7 0C? c) If 31.65 kJ are transferred to this gas at constant

volume, what are the resulting temperature and pressure?

A spherical balloon is 40 ft in diameter and surrounded by air at 60 0F and

29.92 in Hgabs. If the balloon is filled with hydrogen at a temperature of 70

0Fand atmospheric pressure, what total load can it lift? R of hydrogen is

766.54 ft-lbf/lbm-R. (2381 lb)

A 10 ft3 tank contains gas at a pressure of 500 psia, temperature of 85 0F and

a mass of 25 lbm. A part of the gas was discharged and the temperature and

pressure changed to 70 0F and 300 psia, respectively. Heat was applied and

the temperature was back to 85 0F. Find the final mass, volume and pressure

of the gas. (15.43 lbm, 10 ft3, 308.5 psia)

It takes 36 sec for 0.01 moles of He to effuse through a pinhole in an effusion

apparatus. It takes 72 sec for 0.01 moles of another gas to effuse through the

same system. What is the molecular weight of the unknown gas?

A machinist wishes to insert a brass rod with a diameter of 2 mm into a hole with a diameter of 1.995 mm. By how much would the machinist have to lower the temperature (in °C) of the rod to make it fit the hole?

 Two bodies A and B in figure are separated by a spring. Their motion down the incline is resisted by a force P = 800 N . The coefficient of kinetic friction is 0.30 under A and 0.10 under under B. a.) compute the acceleration of block A b.) Compute the acceleration of block B c.) Determine the force in the spring. *

An automobile starting from the rest speeds up to 15 m/sec. with a constant acceleration of 1.2 m/sec^2 , runs at fast speed for sometime and finally comes to the rest with the deceleration of 1.5 m/sec ^2 . If the total distance travelled is 400 m find the total time required. *

The acceleration of a point is a= 30t m/s^2. When t= 0, s=50 m, and V= 15 m/s. a.)What is the position of the point at t=3 sec? b.) What is the velocity of the point at t= 3 sec? c.) What is the acceleration of the point at t= 3 sec? *

 A feather is dropped on the moon from a height of 1.40 meters. The acceleration of gravity on the moon is 1.67 m/s^2. Determine the time for the feather to fall to the surface of the moon. *

work done on the steady flow system is 30 kJ/kgm. Calculate the heat in HP 

if the mass flow rate of fluid is 10 kg per minute given that the internal energy 

is decreased by 10 kJ/kgm and the fluid flow is increased by 20 kJ/kgm. Also, 

identify if the heat is added to the system or rejected by the system