Who first proved that the sun is not at or even close to the center of the milky way galaxy?

Aplayground merry-go-round has a radius of 4.6 m and a moment of inertia of 200 kg-m2 and turns with negligible friction about a vertical axle through its center. a child applies a 26.0 n force tangentially to the edge of the merry-go-round for 15.0 seconds. if the merry-go-round is initially at rest, how much work did the child do on the merry-go-round?

The molecular mass of a gas is (select all that apply) a. independent of the type of gas b. the same number as the atomic (or molecular) mass, but measured in grams c. dependent on the temperature d. the mass of a mole of the gas

Nancy is playing on a ladder and slide. the entry point of the slide is 3.0 meters above the ground and the slide is inclined at an angle of 30.0° with the horizontal. what is nancy's displacement each time she slides down from the top?