Elephants can communicate using very low frequency sound waves over long distances. An elephant makes a noise below human hearing at 16Hz. This low rumble moves at 350 m/s (speed of sound in air). This sound is detected by her friend 25 seconds later.
How far away is her friend?

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c

High schoolphysics 5+3 pts a neon light consists of a glass tube with metal wires at each end. when connected to a high-voltage source, the gas glows. if a fly lands on the glass tube, what will most likely happen? a) the fly will not feel a shock because the glass conducts any free electrons back into the gas. b) electrons will flow directly from the metal wires along the glass and shock the fly. c) the fly will not feel a shock because the glass insulates it from the electrons in the gas and the metal. d) electrons that are moving through the gas will be conducted through the glass and shock the fly.

Suppose that f : rn → rm and that a ∈ k, where k is a connected subset of rn . suppose further that for each x ∈ k there exists a δx > 0 such that f(x) = f(y) for all y ∈ bδx (x). prove that f is constant on k; that is, f(x) = f(a) for all x ∈ k