Light, Lenses and How the Eye Works

Transmitted

goes through

Absorbed

“blocked”

Reflected

“bounces back”

In reflection, the angle of incidence and the angle of reflection are?

the same

Refraction

when the light bends due to a change in medium density

When entering a denser medium, the relationship between the angle of incidence and the angle of refraction is?

incidence > refraction

When entering a less dense medium, the relationship between the angle of incidence and the angle of refraction is?

incidence < refraction

When a convex lens is thicker, the focal point is closer, meaning the focal length is?

shorter

When a convex lens is thinner, the focal point is further away, meaning the focal length is?

shorter

Why can we see the sun’s light but not hear its explosions?

because space is a vacuum and sound needs particles to travel in but light doesn’t

Transverse

vibrations that are perpendicular to the direction energy is travelling in

Longitudinal

vibrations that are parallel to the direction energy is travelling in

Equation for wave speed?

wave speed = wavelength × frequency

White light is made up of how many colours?

7

Which colour of light has the lowest frequency?

red

Which colour of light has the highest frequency

purple

Explain how the eyes work?

1. the eye senses light and alters the size of the iris to limit the amount of light coming into the eyes

2. muscles change the thickness of the lens depending on how near or far the object is

3. the light is focused by your cornea and lens on to the retina

4. the light sensitive cells in your retina send electrical impulses through the optic nerve to your brain

5. your brain processes this impulses and shows you what the objects look like

Speed of sound?

340m/s

Speed of light?

300,000,000m/s

How do we see colour?

what colour we see depends on what colours are reflected and absorbed- for example, a red shirt would absorb all colours except red, which would be reflected