Initially there are 3 [kg] of gas at a pressure of 200 [kPa] and specific volume of 1.5 [m3/kg] contained within a piston cylinder assembly. The gas undergoes a polytropic process for which P∀2=constant until the specific volume is 1.0 [m3/kg] and the specific internal energy decreases by 150 [kJ/kg]. Find the amount of heat transfer between the system and surroundings in [kJ].

-900 kJ

Explanation:

Q = ∆U + W

The specific internal energy decreases by 150 kJ/kg, therefore, change in internal energy (∆U = -150 kJ/kg × 3 kg = -450 kJ)

W = (P2V2 - P1V1)/1-n

P2 = P1(V1/V2)^n

P1 = 200 kPa

V1 = 1.5 m^3/kg × 3 kg = 4.5 m^3

V2 = 1 m^3/kg × 3 kg = 3 m^3

n = 2

P2 = 200(4.5/3)^2 = 450 kPa

W = (450×3 - 200×4.5)/1-2 = -450 kJ

Q = -450 + (-450) = -450 - 450 = -900 kJ

8 meters above the spring

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.