Motion in the universe Flashcards
What does the size of force depend on ?
1.masses of two objects
2. distance between masses
What is a satellite ?
It is an object that orbits a planet .
Uses of satellites
Large distance - international calls /internet
Short distance - tempo/forest fire
What are comets ?
Tghey are large rock peices of ice that orbit the Sun .They have very elliptical orbits .
Relationship with Gravitational field strength and
Larger the mass of a planet the greater the GVF
The larger the radius of a planet the smaller the gravitational field strength at its surface .
Moon mass and Earths
Moons mass is 1/6 of the Earth
Orbital speed
speed = distance / time for one complete orbit
Distance formulae
2 x pi xorbital radius
Hot stars
blue to white to yellow to orange to red
Ways to find the brightness of a star
Apparrent brightness of a star and magnitude
Absolute brightness and magnitude
luminosity - amount of energy in the form of light is emiited from a star’s surface every sec
How is a star formed ?
what ios evidence for Big Bang theory ?
Red shift o The red shift of light from galaxies shows that they are all moving away from us and that those which are furthest away are moving the fastest, suggesting that the universe was formed from an explosion at a single point, evidence for the Big Bang. This is the principle of the Doppler effect. ● Cosmic microwave background radiation (CMBR) o Just after the Big Bang, lots of short wavelength radiation should have been released. This radiation, as the universe expanded over time, would have been stretched to become microwaves. o The fact that there is cosmic microwave background radiation present wherever you point a telescope in the sky provides evidence for the Big Bang.
