Abaseball is travelling (+30 m/s) and is hit by a bat. it leaves the ball travelling (-40 m/s) what is the change in velocity

Hydrogen and helium are both members of?

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?

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?