Refrigerant-134a enters the expansion valve of a refrigeration system at 120 psia as a saturated liquid and leaves at 20 psia. Determine the temperature and internal energy changes across the valve.

Física: un futbolista patea hacia el arco con una velocidad de 15m/ah, calcular: a)el alcance para un ángulo de tiro de 25? , b) el tiempo que el balón permanece en el aire.

On mars a rock falls an unknown vertical distance from a resting position and lands in a crater. if it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? mars' surface gravity is 3.8 m/s2.

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?