Fig P1135 1136 A group of students launches a model rocket i

Fig. P11.35 11.36 A group of students launches a model rocket in the va the ven direction. Based on tracking data, they determine that the alt of the rocket was 89.6 ft at the end of the powered rtion of flight and that the rocket landed 16 s later. Knowns descent parachute failed to deploy so that the rocket fell freely iu the ground after reaching its maximum altitude and assuming tha 89.6 32.2 f/s, determine (a) the speed vi of the rocket at the enl of powered flight(b) the maximum altitude reached by the rocket Fig. P11.36

Solution

time taken by the rocket to ground is t = 16.0 sec

        total height reacher h = gt ^2 / 2

                                              = 32.2 * 16 * 16 /2 = 4121.6 ft

   let v be velocity at the end of the power fllight

                        height reach from that point of power flight = total height - 89.6ft

                                    velocity v   = sqrt (2g h´) = 2*3.2.2 * (4121.6 - 89.6)

                                        = 509.56 ft / sec