1140 Questions & Blanks Flashcards
Why did scientists abandon Isaac Newton’s particle theory of light in 1850?
Jean Foucault discovered that light travels slower in water than in air.
Why do scientists have difficulty discovering truth?
They have a limited means of observing reality.
What are light waves?
The regular and rapid transverse vibrations of electric and magnetic fields that spread out evenly in all directions.
The frequency of sound is interpreted by the ear as ______
Pitch
The frequency of light is interpreted by the eye as:
Color
Six basic colors of the visible light spectrum
Red orange yellow green blue violet
The brightness of light is measured by its __________
Intensity or amplitude
The inverse square law for light intensity (brightness)
The intensity of light at a particular point is inversely proportional to the square of the distance of the object from the light source.
Light must be allows to expand in a spherical shell for the inverse square law to apply.
.
Four physical quantities that vary according to the inverse square law
The force of gravity Brightness of light Intensity of sound Magnetic fields Electrical fields
What did William Herschel conclude about the sun?
It radiates invisible waves
Infrared waves have a _______ than do visible light waves.
Longer wavelength
A blacktop road that is warmer than air
Radiates heat efficiently
Black dirt
Absorbs and radiates heat efficiently
A blacktop road that is cooler than the air
Absorbs heat efficiently
Aluminum foil
Absorbs and radiates heat poorly
Microwaves, radar, UHF, VHF, FM, AM
Increasing wavelength
Decreasing frequency
.
All electromagnetic waves can be _________
Reflected, refracted, or absorbed
Huygen’s principle of wave motion
Every point on a wave is itself a source of a new wave motion of the same frequency
What is diffraction?
a phenomenon in which waves spread out after they pass through a small opening and bend as they pass along the edge of an obstruction
When water waves strike a small standing obstruction, such as a post, they:
bend along the edge of the obstruction
How does diffraction affect microscopes and telescopes?
it limits their resolution