Topic 4 - Astrophysics and Cosmology Flashcards Preview

Edexcel Physics IAL unit 5 > Topic 4 - Astrophysics and Cosmology > Flashcards

Flashcards in Topic 4 - Astrophysics and Cosmology Deck (8)
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1
Q

Differences and similarities between electric fields and gravitational fields

A

:

2
Q

Electric fields are both attractive and repulsive while gravitational fields are always attractive
Electric fields are stronger than gravitational fields

A

However they are both radial from a point

3
Q

Flat universe

A

When the universe expands to a constant size

4
Q

Closed universe

A

The universe will stop expanding at some point and then collapse again

5
Q

Open universe

A

Universe could continue expanding forever

6
Q

Scientists can’t calculate the density of the universe

A

We can measure the mass of all the stars in the galaxy from its luminosity

7
Q

Galaxies rotate which means that all the stars they contain must be experiencing a centripetal force towards the Centre of the galaxy’s rotation.

A

When the rotational speed is measured, the mass suggested by the luminosity calculations is not nearly enough to create the centripetal force needed to keep the Galaxy spinning

8
Q

This suggests that the galaxies must contain a lot of mass that does not emit light

A

No one knows what the dark matter could be