Astronomy Conservation Laws Flashcards
Why do objects move at constant velocity if no force acts on them?
The conservation of momentum
What is the conservation of momentum?
The total momentum of interacting objects cannot change unless an external force is acting on them. Interacting objects exchange momentum through equal and opposite forces
What keeps a planet rotating and orbiting the sun?
Angular momentum! (mass x velocity x radius)
Can angular momentum change?
Only if an external twisting force is acting on it (torque). Earth experiences no twisting force as it orbits the sun, so its rotation and orbit will continue indefinitely
What is energy and what does it do?
Can make matter move and can be conserved; however it can also transfer from one object to another and change form
What is radiative energy?
Light energy
What is thermal energy?
The collective kinetic energy of many particles. All objects contain thermal energy.
Is thermal energy the same as temperature?
No, it is only related to temperature. Temperature is the average kinetic energy of many particles
How are temperature scales used?
Thermal energy measuring depends on temperature and amount of matter
What does gravitational potential energy depend on on earth?
- Objects mass
- strength of gravity
- distance object could potentially fall
What does gravitational potential energy depend on in space?
When an object is spread out it has more gravitational potential energy than when it contracts
What does a gas cloud convert gravitational potential energy into?
Thermal energy
What is mass energy?
A type of potential energy (E = mc^2). Small amount of mass can release a lot of energy (a bomb). Concentrated energy can sometimes turn into particles
