PLEASE HELP FAST!!!
What is the primary source of a sound?
A. A frequency
B. A refraction
C. A vibration
D. A medium to carry the signal

Which of the following best describes reverberation?
A. The wavefronts become mixed and broken up due to contact with a rough or irregular surface.
B. A fraction of the sound waves are absorbed by an object and converted to heat energy.
C.A single sound undergoes several reflections due to multiple reflecting surfaces.
D.A change in the sound wave velocity causes the wave to bend in a different direction.

_______ occurs when a body’s molecular wavelength sends vibrations to another body, resulting in the production of another sound wave.
A. Focusing
B. Refraction
C. Interference
D. Resonance

Which of the following is an example of the Doppler effect?
A. Two identical musical instruments being played next to each other will produce a sound twice as loud as if only one were played.
B. Vibrations from a tuning fork pass through the air and cause a nearby dish of water to produce ripples of the same frequency.
C. A hiker shouts "hello" into a canyon and hears it repeated back several times before it fades away.
D. The siren of a police car sounds different when the car is coming toward you than it does when it passes you.

In Sir Isaac Newton's time in the early 1700s, what was the general consensus among scientists on the properties of light?
A. Light travels in waves and can, as a result, bend slightly around obstructions.
B. Light requires a medium for self-propagation and can't pass through a vacuum.
C. Light represents the release of electrons when energy is applied to an object.
D. Light is composed of particles and travels in a straight line.

If the angle of incidence of a light source to a shiny surface is 30 degrees, what will the angle of reflection be?
A. 150 degrees
B. 60 degrees
C. 30 degrees
D. 90 degrees

If a material has a high index of refraction, it has a
A. low optical density, and light travels more slowly through it.
B. high optical density, and light travels more slowly through it.
C. high optical density, and light travels more quickly through it.
D. low optical density, and light travels more quickly through it.

Which of the following statements regarding the visible spectrum of light is accurate?
A. The wavelength of visible light falls between gamma rays and X-rays along the spectrum.
B. It represents only a very small fraction of the entire electromagnetic spectrum.
C. It can be detected only through the use of thermal imaging equipment.
D. It has the longest wavelength of all types of waves along the electromagnetic spectrum.

If you were to combine a beam of blue light and a beam of yellow light, what would the result be?
A. White light
B. No light
C. Green light
D. Black light


The type of light waves that living things give off naturally is called
A. radio waves.
B. infrared light.
C. gamma radiation.
D. visible light.

When you're standing in a pool in the summertime, and your leg looks shorter under the water than in air, this is an example of light
A. absorption.
B. refraction.
C. reflection.
D. resonance.