A person on a scale rides in an elevator. If the mass of the person is 70.0 kg and the elevator accelerates upward with an acceleration of 2.90 m/s2, what is the reading on the scale?

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?