Waves and Radiation Flashcards
(13 cards)
Wave speed Equation
Frequency x wavelength
Transverse waves
In transverse waves, the oscillations (vibrations) are perpendicular to the direction of energy transfer
Longitudinal Waves
The oscillations are parallel to the direction of energy transfer.
Waves can be….
Absorbed, transmitted and reflection
Angle of incidence =
Angle of reflection
Reflection can be specular or diffuse
Specular reflection happens when a wave is reflected in a single direction by a smooth surface.
Diffuse reflection is when a wave is reflected by a rough surface and the reflected rays are scattered in lots of different directions
Name a Radioactivity substances ?
Uranium and Plutonium
What does a radioactive substance contain?
It contains an unstable nuclei that becomes stable, by emitting radiation
Is radioactivity predictable when it will happen
No it is a random process
Describe Alpha radiation?
Alpha is stopped by paper and has a range of few cm in air. It hads the greatest ionising power.
Describe Beta radiation
Beta radiation is high energy electrons, stopped by thin sheet of metal, range about 1 metre in the air. Is more ionising than Gamma.
Describe Gamma radiation
Gamma ray is stopped by thick lead and has an unlimited range in air. It is most penetrating.
Equipment for measuring Radiation?
Geiger counter
1) Measure count rate without material
2) Measure count rate with material
