Physics Paper 2 Topics Flashcards
Describe the lifecycle of a star
The life cycle of a star:
1) . starts as dust and gas cloud
2) . gravity pulls dust and gas together
3) . forms a protostar
4) . stars get denser and temp rises
5) . main-sequence star formed
6) . hydrogen nuclei run out and star fuses with heavier elements
7) . either red giant or red super giant forms
8) . red giant > white dwarf > black dwarf
9) . red super giant > supernova > smaller stars (neutron stars) or giant stars (black holes
What does the solar system contain?
The solar system contains 8 plants, the sun, dwarf planets, moons and satellites
What do planets orbit?
Planets orbit the sun
What do moons orbit?
Moons orbit planets
What are circular orbits?
Circular orbits are when gravitational force keeps planets and satellites in circular orbits
What do circular orbits cause?
Circular orbits cause objects direction and speed to constantly change
In a stable orbit, if the speed of an object changes, what happens?
If the speed of an object changes whilst in a circular orbit, the radius of orbit changes. If there is a smaller radius, the object travels faster
What is red-shift?
Red-shift is the observed increase in the wavelength of light (light shifting toward the red end of the spectrum)
When is red-shift observed?
Red-shift is observed when a galaxy moves further away from the earth
What does mean if there is a large distance between the earth and a galaxy?
Distance between earth and galaxy causes the galaxy to move further away from us and results in a greater red-shift
What is the big bang theory?
The big bang theory is the theory that all matter in the universe occupied a small and hot tiny space which eventually exploded and expanded
What are 3 things that are not fully understood in the universe?
3 things that are not fully understood in the universe include the increasing distance from galaxies, dark matter and dark energy
What does it mean by the pressure of a fluid?
Fluid pressure is a measurement of the force per unit area
How much pressure will be exerted on a fluid with a low density?
Low density - Low pressure
How much pressure will be exerted on a fluid with a high density?
High density - High pressure
What is a scalar quantity?
A scalar quantity is a quantity with magnitude only
What is a vector quantity?
A vector quantity is a quantity with magnitude and direction
Examples of scalar quantities
Examples of scalar quantities include speed, mass, temperature and time
Examples of vector quantities
Examples of vector quantities include velocity, force and displacement
Examples of contact forces
Examples of contact forces include air resistance, friction
Examples of non-contact forces
Examples of non-contact forces include gravity, magnetism and nuclear
How do you calculate weight?
Weight = mass x gravitational field strength
How do you calculate the resistance force when the forces are acting in the same direction?
When forces are acting in the same direction, you add the forces to calculate the resistance force
How do you calculate the resistance force when the forces are acting in the opposite direction?
When forces are acting in the opposite direction, you subtract the forces to calculate the resistance force
What do the arrows represent on a forces diagram?
Arrows represent the size of the force and the direction
How do you calculate speed?
Speed = distance divided by time