Physics 4.6 - 4.10 Flashcards
What is a real image
A real image is an image that is formed when light rays converge to a single point called the focal point
What is a virtual image
A virtual image is an image that is formed from virtual rays when the light rays appear to diverge
What is a focal point / principal focus
A focal point is a point at which light rays converge to or diverge from
What is an optical center
An optical center is a point at the center of the lense
What is a focal length
A focal length is the length from the optical center to the principal focus or focal point
What type of image is formed when an image is less than a focal length away from a convex lens
A virtual image
At least how many rays should you draw when constructing a ray diagram?
2
Where should those rays go?
One straight ray from the tip of the object to the lens
One ray from the tip of the object to the optical center
How do we find the image formed from those two rays?
We get the point at which those rays intersect
Why does an object appear red?
Explain in terms of light reflection or transmission (light passing through an object)
Because it’s reflecting or transmitting the red wavelength or reflecting or transmitting two or more other colors that combine to make red
____ light is a combination of all colors
White
____ is the absence of light
Black
Name the three primary colors of light
Red
Green
Blue
Name each wave in the electromagnetic spectrum from longest wavelength to the shortest
Radio waves
Micro waves
Infra red
visible light
ultra violet
xray
gamma
Which waves in the electromagnetic spectrum are used for communication?
Radio and micro waves
Which waves are ionizing in the electromagnetic spectrum?
Ultra violet, xray, gamma
Which wave in the electromagnetic spectrum gives off heat?
Infrared
What kind of waves are the waves in the electromagnetic spectrum? (Longitudinal, Transverse)
Transverse
What speed do electromagnetic waves travel in a vacuum?
3*10^8 m/s
Name the 3 types of radio waves
Long waves
Short waves
Very short waves
How far can long waves travel and why?
Very far because they get diffracted by the earths curvature like gravity assist XD
How and how far do short waves travel?
They travel by being reflected by the earth and it’s ionosphere, which allows them to travel long distances but shorter than long waves
How and how far do very short waves trave;
They travel short distances from transmitter to transmitter which is why buildings and tunnels may disrupt the signal
