Alright, time to take a break for a while. You've been working too hard and need some dopamine in your life. Here is 100 points, free of charge. First come first serve, and everyone who answers should get 5 stars ;).

How many times did thomas edison mess up the light bulb

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?