what is the speed of wave if the frequency is 50HZ and wavelength is 4000000nm? * 20mm/s 2m/s 2000000nm/s 0.02m/s 200µm/s 20cm/s

A car is speeding away from a policeman at 45 m/sec. Police radar operates at 10 GHz. The frequency of the radar signal reflected from the car is (a) 3.0 kHz more than 10 GHz (b) 1.5 kHz less than 10 GHz (c) 1.5 kHz more than 10 GHz (d) 3.0 kHz less than 10 GHz (e) 1.3 kHz less than 10 GHz

IX. Suppose we use microwave radar to measure the height of the substance in the tank, and the time from the signal sent to the signal received by the radar is 3.502423×108 seconds. Assume that the height of the tank body is 20m, and the microwave speed is 299792458m/s. Compute the height of the substance. H=? Microwave Radar 20m

Block A rests on a horizontal tabletop. A light horizontal rope is attached to it and passes over a pulley, and block B is suspended from the free end of the rope. The light rope that connects the two blocks does not slip over the surface of thè pulley (radius 0.080 m) because the pulley rotates on a frictionless axle. The horizontal surface on which block A (mass 3.70 kg) moves is frictionless. The system is released from rest, and block B (mass 6.00 kg) moves Part A What is the tension force that the rope exerts on block B? downward 1.80 m in 2.00 s. Express your answer with the appropriate units. HÁ TB = Value Units Submit Request Answer Part B What is the tension force that the rope exerts on block A? Express your answer with the appropriate units. HẢ 王新 TA= Value Units