What is the net force as shown in this diagram that represents a game of tug-of-war? 40 N
20 N

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

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.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.