A pulley stated from rest is given an acceleration of 0.5rad/s^2.what will be it's speed in r. m.p at rate of 0.3rad/s^2 In how many minutes the pulley will come to rest​

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?