Consider a bright star in our night sky. Assume its distance from Earth is 86.3 light-years (ly) and its power output is 4.00 × 1028 W, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m² (b) Find the power of the starlight the Earth intercepts. (The radius of Earth is 6.38 x 106 m.) MW Need Help? Read It

A 40.0 W incandescent light bulb transforms 19.0% of its energy into visible light; the rest goes largely to non-visible infrared radiation. At what distance from the bulb is the amplitude of the electric field of the visible-light wave 13.1 V/m? Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer units

What inductance must be connected to a 17 pF capacitor in an oscillator capable of generating 550 nm (i.e., visible) electromagnetic waves? Comment on your answer.

An electromagnetic wave with frequency 5.70 * 10^14 Hz propagateswith a speed of 2.17 * 10^8 m/s in a certain piece of glass. Find the dielectric constant for glass at this frequency, assuming that the relative permeability is unity.

A 10.0%-efficient array of solar cells collects sunlight with an average intensity of 700W/m2. (a) In order to absorb energy at a rate of 100W, what total area must the array have? (b) If the array were to pay for itself in two years, what is its maximum cost of the array, assuming it operates for 10.0 h per day, earning 9.00¢ for each kilowatt-hour collected?

Estimate the rms electric field in the sunlight that hits Mars,knowing that the Earth receives about 1350 W/m2 and thatMars is 1.52 times farther from the Sun (on average) thanis the Earth.

28 Consider a bright star in our night sky. Assume its distance from Earth is 29.0 light-years (ly) and its power output is 4.00 x 104° w, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m? (b) Find the power of the starlight the Earth intercepts. (The radius of Earth is 6.38 × 10° m.) MW Need Help? Read It

Assume the helium-neon lasers commonly used in student physics laboratories have power outputs of 0.250 mW. (a) If such a laser beam is proje ted onto a circular spot 3.50 mm in diameter, what is its intensity (in watts per meter squared)? W/m² (b) Find the peak magnetic field strength (in teslas). T (c) Find the peak electric field strength (in volts per meter). V/m

Consider a bright star in our night sky. Assume its distance from Earth is 84.9 light-years (ly) and its power output is 4.00 × 1028 W, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m² (b) Find the power of the starlight the Earth intercepts. (The radius of Earth is 6.38 x 106 m.) MW

An MRI technician moves her hand from a region of very low magnetic field strength into an MRI scanner's 2.00 T field with her finger pointing in the direction of the field.An MRI technician moves her hand from a region of very low magnetic field strength into an MRI scanner's 2.00 T field with her finger pointing in the direction of the field. Find the average emf, in millivolts, induced in her wedding ring given its diameter is 2.41 cm, and assuming it takes 0.487 s to move it into the field.