A rubber ball that sits motionless near the edge of a tall bookshelf has no kinetic energy. However, it does have mechanical energy. Explain why this is possible,

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered

i'm on my way to history not a mistory.