Jane waits on a railroad platform while two trains approach from the same direction at equal speeds of 7.10 m/s. both trains are blowing their whistles (which have the same frequency), and one train is some distance behind the other. after the first train passes jane but before the second train passes her, she hears beats of frequency 6.50 hz. what is the frequency of the train whistles

Fill in the blank. the number of each type of element in the compound (other than 1) is represented by a small number to the right of the element symbol.

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?