Aweather emergency siren is mounted on a tower, 129 m above the ground. on one hand, you would like to make the siren very loud so that it will warn as many people as possible. on the other hand, safety regulations prohibit you from exceeding an intensity level of 111 db for workers standing on the ground directly below the siren. assuming that the sound is uniformly emitted, what is the maximum power that the siren can put out?

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?

Asystematic approach to problem solving is called a (an)

The two stars in a certain binary star system move in circular orbits. the first star, alpha, has an orbital speed of 36 km/s. the second star, beta, has an orbital speed of 12 km/s. the orbital period is 137 d. a) what is the mass of the star alpha? b) what is the mass of the star beta?