Astrophysics

Question 1

The size of the gravitational force depends on:

Answer 1

• Mass

- Distance

Question 2

Which planets follow the most curved path?

Answer 2

Those closest to the Sun

Question 3

Artificial satellites put into lower orbits are used for:

Answer 3

• Monitoring the Earth’s surface: Temperature of oceans

: Progress of forest fires

Question 4

What are comets?

Answer 4

Large rock-like pieces of ice that orbit the Sun in elliptical orbits

Question 5

What is gravitational field strength?

Answer 5

The strength of gravity on a planet or moon (g)

Question 6

The size of the gravitational field strength depends on:

Answer 6

• Mass of the celestial body

- Radius of the celestial body

Question 7

Orbital speed (v) =

Answer 7

2 x ⫪ x r / T

Question 8

What type of galaxy is the Milky Way?

Answer 8

Spiral galaxy

Question 9

The color spectrum of stars from hot to cold:

Answer 9

Blue (O)
    ⬇
Blue-white (B)
    ⬇
White (A)
    ⬇
Yellow-white (F)
    ⬇
Yellow (G)
    ⬇
Orange (K)
    ⬇
Red (M)

Question 10

What does the brightness of the star depend upon?

Answer 10

• The distance from the Earth
• Luminosity of the star
• What the star is made up of and what nuclear reactions are going on at the time

Question 11

Three ways in which the brightness of the stars is determined:

Answer 11

• Apparent brightness from the Earth
• Absolute brightness of the Sun (standard distance = 32.6 light-years)
• Luminosity of the star (energy emitted per second)

Question 12

The life cycle of a star:

Answer 12

Nebula
⬇
Protostar
⬇
Main sequence star
⬇
Nuclear fusion ends, star shrinks, becomes very
hot, helium fusion, outward pressure, energy
released, expands, cooler, emits red light
↙ ↘
Red giant Red supergiant
⬇ ⬇
Most of the helium fused, As it contracts: unstable Compressive forces are larger ⬇
Star contracts, hot Supernova (nebula)
⬇ ↙ ↘
White dwarf Neutron Blackhole
⬇ star
Black dwarf

Question 13

Explain the Big Bang theory?

Answer 13

The Big Bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching).

Question 14

What are the two pieces of evidence given for the Big Bang theory?

Answer 14

Red-shift and CMBR

Question 15

Write the Doppler equation

Answer 15

change in wavelength/reference wavelength = velocity of galaxy/speed of light