To navigate, a porpoise emits a sound wave that has a wavelength of 4.9 cm. the speed at which the wave travels in seawater is 1522 m/s. find the period of the wave.

Porque crees que el agua no podia subir mas de 10 m de altura con ese tipo de bomba

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?

Explain why electric current cannot exist if a current doesn't have a voltage source.