Molecules are groups of atoms connected together. Which substances in the simulation have particles that are molecules?

What are similarities and differences of reflection, refraction, diffraction and absorption?

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.