3. A dog walks a distance of 100 ft. in 20 s of time. What is the dog's speed in feet per second?
O C 120 ft/s
O B80 ft/s
O D 2000 ft/s
O A 5 ft/s

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

The movement of electrons between atoms is called an

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?