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.

Hen a gfci receptacle device is installed on a 20-ampere branch circuit (12 awg copper), what is the minimum volume allowance (in cubic inches) required for conductor fill for each conductor in the outlet box?

Tafari worked one summer on a ship that set weather buoys in the ocean. he watched how one of the buoys moved in the water. describe which parts of the wave would cause the buoy to bob up and down. which wave property determined how fast the buoys bobbed in the water? he observed that when the wind blew harder, the ocean waves were larger, and the buoys moved away from the ship. what effect, if any, did the waves have on how far the buoys moved? explain your answer.

The rocket is fired vertically and tracked by the radar station shown. when θ reaches 66°, other corresponding measurements give the values r = 32700 ft, r¨ = 85 ft/sec2, and θ˙ = 0.019 rad/sec. calculate the magnitudes of the velocity and acceleration of the rocket at this position.