Light and Seismic Waves Flashcards
What type of wave is light?
Electromagnetic waves
How fast does light travel in m/s?
3x10^8 m/s in space and in air however its slower in denser materials such as glass
Describe the law of reflection
The angle of incident is the same as the angle of reflection
It was written in the booklet, help
What is the normal line on a ray diagram?
Where you measure angle of incident and reflection
What is refraction of light?
The process of a light ray both changing speed and changing direction
What happens when light goes from low to high density?
Slows done and refracts towards normal
The denser the material, (light)…
The more the light refracts
Angle of incidence is…?
Outside
Angle of refraction is…?
Inside
If incident angle is less than critical angle?
Light is refracted
If incident angle equal to critical angle?
Light is refracted and a bit reflected
If incident angle greater than the critical angle?
Light is reflected
What 2 conditions must be met for light to be trapped inside an optical fibre?
· Layer of less dense glass
· Angle needs to be greater than critical angle
6 advantages and 2 disadvantages of CT Scan?
Advantages: · Images larger areas of internal body · 3D representation of images on computer screen · Clear image of body tissue and bones · Painless · Can image inside organs · No physical examination
Disadvantages:
· Exposure to high doses of ionising radiation is dangeroes
· Not recommended for pregnant women/young children
Advantages and disadvantages of Endoscopy?
Advantages:
· Body organs and structures directly viewed and given clear pictures of surface features
· Biopsy can be done at same time. Taking direct tissue samples using a tool attachment
· No long term health problems
Disadvantages:
· Uncomfortable for patients
· Only the surface of organs can be seen
