The following graph depicts the change in energy per second of an 84.0 kg boulder as it falls off a cliff to the ground.

After 3 seconds, what is the approximate speed of the boulder?
833 m/s
3.00 x 104 m/s
O 3.50 x 104 m/s
28.9 m/s

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.