If the frequency of a sound wave is 990 Hz, calculate its wavelength.

Which description best explains why the view within the rectangle lens is different than the view outside the lens? Light waves are restricted to a single plane through the lens.

Explain that a universe is a large collection of billions of galaxies and is expanding continuously?

What does not affect the gravitational potential energy of an object

The ultimate fate of our universe depends on its mass. true or false.

How do objects appear to have color

An unknown fluid has a specific gravity of 0.750. What is the volume of 22.5 kg of this fluid? A. 10 L B. 20 L C. 30 L D. 40 L

What kind of tide is responsible for extreme tides

What does the speed of sound depend on? A. Medium that the sound travels through B. Acoustics C. Frequency of the sound D. Loudness of the sound

Which of these is not a source of the shock waves that lead to protostars?

Which kind of information is known about a person if that person's DNA is in a database? A. how old the person is B. where the person was probably born C. some diseases the person might have D. whether the person is likely to commit a crime