A soccer ball kicked due west during a practice collides with a rock that is initially at rest. Just after the collision, the ball is moving toward the southeast. Just after the collision, the rock must be moving toward the: a. northwest
b. southeast
c. southwest
d. west.
e. northeast.

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.