Asled and rider (combined mass of 69 kg) finish a downhill run with a speed of 30 m/s, then enter a flat (horizontal) area where the sled slows down at a constant rate of -2.3 m/(s^2) until it stops. what distance did the sled move while slowing down?

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?