A chemical engineer claims to have devised a closed device, operating isothermally at 300 K, that could expand 100 mol of methane (assumed to be an ideal gas) from 1.0 to 0.4 MPa, and in the process generate 250 kJ of useful work. Should we believe this claim? Answer the question by calculating the change in entropy of the system, the change in entropy of the surroundings, and the total change in entropy of the universe.

Fluids at rest possess no flow energy. a)- true b)- false

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?