Does gravity decrease when mass decreases and does gravity decrease when distance increases

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Which type of basaltic lava flow has a fairly smooth

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.