Students are collecting data as they control the toy helicopter shown. The helicopter has a mass m and must exert a thrust of power P0 to initially move upward with a constant speed v0 . The students then cause the helicopter to exert a thrust so that a net force Fnet=2mg accelerates it upward. As the helicopter is accelerating, it has a thruster power Pf , and as it passes a height h0 it has a speed of 3v0 . The ratio PfP0 is most nearly

Write short note on the following ; collision theory, rotation angle and angular velocity, centripetal acceleration, coriolis force, and newton's law of gravitation.

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?