Which of the following lenses has at least one plane surface?
a. double-convex lens
b. converging concavo-convex lens
c. double-concave lens
d. plano-convex lens

Aballet student who learns with the of his instructor is demonstrating learning.

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?

What is an aquifer for science class