Awire of circular cross-section carries current density that is not uniform but varies with distance from the center as j(r) = a r / r, for radius r in the range 0 < r < r. here, a is a constant with units amperes per square meter, and the radius of the wire is r = 8.1 mm. find an expression for the magnetic field outside of the wire, for r > r.

During takeoff, the sound intensity level of a jet engine is 170db at a distance of 34 m. what's the sound intensity level at a distance of 1.0 km?

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?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up