A commuter train passes a passenger platform at a constant speed of 38.3 m/s. The train horn is sounded at its characteristic frequency of 326 Hz. (a) What overall change in frequency is detected by a person on the platform as the train moves from approaching to receding

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?