1.4-1.6

Question 1

Why do satellites remain in orbit?

Answer 1

Travelling so quickly at a horizontal constant velocity and the earth curves downwards at the sane rate

Question 2

What does gravitational field strength depend on?

Answer 2

The mass of the object

Question 3

How do scientists believe stars were formed?

Answer 3

Dispersed matter in the universe being able to bind together by gravity

Question 4

What happens to the speed of light in all reference frames?

Answer 4

The speed of light says the same for all observers in all reference frames

Question 5

What is the minimum velocity at which relativistic effects are observed?

Answer 5

Greater than 10% of the speed of light

Question 6

What is the Doppler effect?

Answer 6

When the frequency of radiation alters as they move away or towards us

Question 7

What is redshift?

Answer 7

How much a spectra has moved towards the low frequency end of the spectrum

Question 8

What direction are galaxies moving that demonstrate blue shift?

Answer 8

Towards earth

Question 9

What is hubbles law?

Answer 9

The speed of distant galaxies is proportional to their distance away
The further away an object is he faster it’s moving away from earth

Question 10

What is recessional velocity?

Answer 10

The velocity at which a distant object is moving away from earth

Question 11

How is the rate of expansion in the universe changing?

Answer 11

As galaxies are found to be accelerating away from us

Question 12

What is dark matter?

Answer 12

Matter than cannot be detected by em spectrum detectors to account for the missing matter in the universe

Question 13

What is the evidence for dark matter?

Answer 13

Gravity causes galaxies to rotate and the rate or rotation depends on the mass:faster spin=larger mass, and when calculating this the mass was greater than expected

Question 14

What is dark energy?

Answer 14

Energy that is not detectable with current astronomical devices to take account for the missing energy in the universe

Question 15

What is dark energy the evidence for?

Answer 15

The rate of expansion in the universe is increasing

Question 16

What is the relationship between the temperature of stellar objects and the wavelength of radiation it emits?

Answer 16

The higher temperature of the star, the smaller the peak intensity wavelength

Question 17

What is the peak wavelength of a stellar object?

Answer 17

The wavelength of a star’s spectrum that has the highest irradiance

Question 18

What is the evidence for the Big Bang?

Answer 18

• cosmological redshift
• cosmic microwave background radiation
• hydrogen and helium in the universe
• olbers paradox

Question 19

What is CMBR?

Answer 19

As the stars in he universe move away from us, their light is redshifted to the microwave section of the spectrum causing an increase in microwave radiation detected

Question 20

What is olber’s paradox?

Answer 20

The fact that there are more stars in the sky than we can see and we cannot see them as their light hasn’t reached us yet, which proves the expanding universe as if it was steady state then we would have seen all stars by now

Question 21

How is abundance of hydrogen and helium in the universe evidence for the expanding universe?

Answer 21

The universe would have been so hot at the beginning that only the simplest of particles could form, which would suggest a high abundance of hydrogen and helium as these are the simplest atoms, which scientists found to be true

Question 22

How is hubble’s law and redshift evidence for expanding universe?

Answer 22

There are far more stars exhibiting redshift than blueshift, (moving away), meaning an expanding universe