Aroller-coaster car moves 172 ft horizontally and then rises 115 ft at an angle of 31.0° above the horizontal. it next travels 115 ft at an angle of 48.0° downward (below the horizontal). what is its displacement from its starting point? (assume the initial horizontal motion of the car to be along the +x axis.)

An ideal otto cycle has a compression ratio of 8. at the beginning of the compression process, air is at 95 kpa and 27°c, and 750 kj/kg of heat is transferred to air during the constant-volume heat-addition process. assuming constant specific heats at room temperature, determine (a) the pressure and temperature at the end of the heat-addition process, (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle. (4390 kpa, 1730 k; 423 kj/kg; 56.4%; 534 kpa)