Arefrigeration cycle operating between two reservoirs receives energy qc from a cold reservoir at tc = 275 k and rejects energy qh to a hot reservoir at th = 315 k. for each of the following cases, determine whether the cycle operates reversibly, operates irreversibly, or is impossible: (a) qc = 100 kj, wcycle = 80 kj. (b) qc = 1200 kj, qh = 2000 kj. (c) qh = 1575 kj, wcycle = 100 kj. (d) β = 8.

28. evolution

29. environment, survive, offspring  

explanation:

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.