2/120. Two cars travel at constant speeds through a curved portion of highway. If the front ends of both cars cross line CC at the same instant, and each driver minimizes his or her time in the curve, determine the distance d which the second car has yet to go along its own path to reach line DD at the instant the first car reaches there. The maximum horizontal acceleration for car A is 0.60g and that for car B is 0.76g. Which car crosses line DD first? 2/121. The fi gure shows a portion of a plate cam used in the design of a control mechanism. The motion of pin P in the fi xed slot of the plate cam is controlled by the vertical guide A, which travels horizontally at a constant speed of 6 in. /sec over the central sinusoidal portion of the slot. Determine the normal component of acceleration when the pin is at the position x = 2 in. 2/122. A football player releases a ball with the initial conditions shown in the figure. Determine the radius of curvature of the trajecto...
Example 2.2 Four kilograms of a certain gas is contained within a piston–cylinder assembly. The gas undergoes a process for which the pressure–volume relationship is The initial pressure is 3 bar, the initial volume is 0.1 m3 , and the final volume is 0.2 m3 . The change in specific internal energy of the gas in the process is u2 u1 4.6 kJ/kg. There are no significant changes in kinetic or potential energy. Determine the net heat transfer for the process, in kJ. Example 2.3 Air is contained in a vertical piston–cylinder assembly fitted with an electrical resistor. The atmosphere exerts a pressure of 1 bar on the top of the piston, which has a mass of 45 kg and a face area of .09 m2 . Electric current passes through the resistor, and the volume of the air slowly increases by .045 m3 while its pressure remains constant. The mass of the air is .27 kg, and its specific internal energy increases by 42 kJ/kg. The air and piston are at rest initially and finally. The piston–cylinder ...