1-ft3 of air is contained in a spring-loaded piston-cylinder device. the spring constant is 6lbf/in, and the piston diameter is 12 in. when no force is exerted by the spring on the piston, the state of the air is 250 psia and 450◦f. this device is now cooled until the volume is one-third its original size. determine the change in the specific internal energy and enthalpy of the air.

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it

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.