A positive charge on an object is caused by:

an excess of protons

an excess of electrons

a deficiency of protons

a deficiency of electrons

Humans can typically perceive frequencies that range from 20 Hz-20 kHz. Dogs can hear sounds up to 45 kHz. Dog whistles produce sound waves that range from 23-54 kHz; therefore, they cannot be heard by the human ear.

What is s the best description of the constructive interference of light? A. two waves have the same direction of displacement. B. two waves have displacement in opposite directions. C. a longitudinal wave meets a transverse light wave D.

An illness caused by protist.

xamine Conceptual Example 3 before addressing this question. A wave moves on a string with a constant velocity. Does this mean that the particles of the string always have zero acceleration?

Why is it expensive to bring electricity into urban areas?

In our physical world, by far, the most abundance free charge in the universe is the electron, which has a negative charge. What do we mean, then, when we say that the surface of an object is positively charged?

You're going camping and are thinking of carrying 3 gallons of water. How much does the water weigh, in units of pounds?

A student is performing a double-slit experiment to determine the wavelength of a light source. She has measured the distance between dark bands and the distance between the slits and the screen.

If a substance cannot be broken down chemically into smaller substances it is A) An element B) a compound C) an atom D) a molecule

Describe the general characteristics of the nearest stars. (Size, luminosity, color, etc., do not include specific stars)