The Expanding Universe

Question 1

When do we hear a slightly higher frequency?

Answer 1

When the source of waves is travelling towards us

Question 2

When do we hear a slightly lower frequency?

Answer 2

When the source of waves is travelling away from us

Question 3

Why do we hear a slightly higher pitch from a source heading towards us than one heading away from us?

Answer 3

As each successive wave is generated from a slightly closer distance, the waves arrive more frequently, increasing the pitch

Question 4

What is fo?

Answer 4

Observed Frequency

Question 5

What is fs?

Answer 5

Source Frequency

Question 6

When calculating the Doppler effect what do you need to remember about the equation?

Answer 6

When a source is moving towards you you subtract (-) the velocity and
When a source is moving away from you your should add (+) the velocity of a source

Question 7

What is redshift?

Answer 7

The spectra of all distant objects are shifted towards the red end of the spectrum; the faster an object is travelling away from the observer the more its spectrum is red shifted

Question 8

What is the symbol for redshift?

Answer 8

z

Question 9

What is the implications of Hubbles law?

Answer 9

If all galaxies are moving away from us the universe is expanding

Question 10

How can you calculate the estimated age of the universe?

Answer 10

By using Hubbles Law and speed, distance time calculations