The equation f = −vex(dm/dt) for the thrust on a rocket, can also be applied to an airplane propeller. in fact, there are two contributions to the thrust: one positive and one negative. the positive contribution comes from air pushed backward, away from the propeller (so dm/dt < 0), at a speed vex relative to the propeller. the negative contribution comes from this same quantity of air flowing into the front of the propeller (so dm/dt > 0) at speed v, equal to the speed of the airplane through the air. for a cessna 182 (a single-engine airplane) flying at 130 km/h, 150 kg of air flows through the propeller each second and the propeller develops a net thrust of 1300 n. determine the speed increase (in km/h) that the propeller imparts to the air.