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.

Which type of current is produced by a wire breaking magnetic field lines and changing the polarity? a. alternating b. direct c. straight d. alternating and direct

What is hidden during a lunar eclipse? isn't the moon hidden?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j.b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.