What is the quality of a measuring instrument, physics? high school physics.

Amplitude is a measure of a waves a; speed b; distance c; energy d; frequency

What is the difference between electrically neutral objects and electrically charged objects

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?