This is called a Rube Goldberg device. It attempts to perform a simple task through a complex series of steps. Most of the time, what is used for each step? A) solar cells
B) simple machines
C) complex machines
D) plants and animals

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

The act of moving from one place to another. a. locomotor b. aerobic c. stationary d. static

Drag each item into the proper state of matter category.