Physics Flashcards
Describe the difference between the geocentric model of the universe and the heliocentric model.
In the heliocentric model all the planets and stars orbit the sun. However in the geocentric model all the planets and stars orbit the earth.
State the type of wave that was used to make early observations and the types of waves and scientists can use today.
Early observations were made used light. Modern observations are also made used with radio, microwaves (and any other named parts of the electromagnetic spectrum.)
Give two ways in which the virtual image in a magnifying glass is different from the real image formed by a lens.
A virtual image is magnified but a real image is smaller.
A virtual image is the right way up but a real image is upside down.
Explain why refraction occurs whenever a wave crosses a boundary between materials.
The speed of the wave changes and this changes the direction of the wave.
Describe one similarity and one difference between refracting and reflecting telescopes.
Similarity: A reflecting telescope eyepiece containing a lens so does a refracting telescope.
Difference: A reflecting telescope uses a mirror to collect light and a refracting telescope uses a lens.
All large telescopes, including the Hubble Space Telescope, are reflecting telescopes. Suggest reasons why reflecting telescopes are used.
It is easier/cheaper to make large mirrors, which are needed to collect more light.
When a wave travels through a material the average position of the particles of the material remains constant. Explain how this is correct for the type of waves found in:
A) A sound wave travelling through the air.
B) Ripples travelling across the surface of a pond.
A) sound waves are longitudinal waves. The particles vibrate in the same direction as the wave travels.
B) Ripples on water are transverse waves. the particles vibrate in a direction at right angles to the way the wave is travelling.
