The cost of a kilowatt hour of energy in the bill is 0.20 euros. A cylindrical led bulb of 5 W has a luminous flux of 50 lm. What is the luminous efficiency of this light source? Knowing that the bulb is 5cm long, 36mm in diameter, and plugged into a 220V socket, what is the resistivity of the bulb? How much would you spend in a year if you used 5 LED bulbs all on for 12 hours a day?

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.

Observations show that interstellar clouds can have almost any shape and

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion