Chapter 10.2

Question 1

Reflection

Answer 1

The change in direction of a light ray when it bounces off a surface

Question 2

Medium

Answer 2

The substance through which light travels

Question 3

Ray

Answer 3

A straight line with an arrowhead that shows the direction of light waves

Question 4

Fermat’s principle

Answer 4

Light follows the path that will take the least time

Question 5

Incident ray

Answer 5

The ray of light that travels from the light source toward a surface

Question 6

Angle of incidence

Answer 6

The angle between the incident ray and the normal in a ray diagram

Question 7

Normal

Answer 7

A line that is perpendicular to the surface

Question 8

Reflected ray

Answer 8

A ray that begins at the point where the incident ray and the normal meet

Question 9

Angle of reflection

Answer 9

The angle between the reflected ray and the normal

Question 10

Laws of reflection

Answer 10

1. The incident ray, reflected ray, and normal always lie on the same plane
2. The angle of reflection is equal to the angle of incidence

Question 10

Plane mirror

Answer 10

A mirror with a flat, reflective surface

Question 11

Virtual image

Answer 11

Images that appear to be coming from a certain position but are not actually from that position

Question 12

What are the characteristics of virtual image?

Answer 12

• Upright
• Above the principal axis
• On the other side relative to the object
• Located behind the mirror

Question 13

Real image

Answer 13

Image that appears inverted and below the principal axis

Question 14

What are the characteristics of real image?

Answer 14

• Inverted
• Below the principal axis
  -On the same side as the object
• Located in front of the mirror

Question 15

Characteristics of image

Answer 15

• Location (closer, farther, or same distance)
• Orientation (upright or inverted)
• Size (larger, smaller, or same size)
• Type (real or virtual)

Question 16

How does stealth aircraft avoid radar?

Answer 16

1. Uses a shape that ensures most radar rays will not return to the radar antenna, but rather to random directions
2. Uses paint that absorbs energy from the radar waves by allowing them to penetrate the surface and reflect from one particle to the next, losing energy along the way until it is too weak for it to be detectable