Units 1-2 Flashcards
True or False: Incline is a factor of acceleration
False
What are the four ways we gain knowledge?
Authority, Intuition, Reason, Sensory Data
Authority
An accepted source of information or advice. You trust them to know best on the issue.
Intuition
The act of knowing or sensing without the use of rational processes. Something like a “hunch” or a “feeling.” Revelation would be included her, as well as immediate cognition.
Reason
Logical, rational, analytic thought - basic intelligence
Sensory Data
Knowledge obtained through the senses.
Why is authority knowledge important?
Because we physically can’t experience everything ourselves. We have to rely on the experiences of others.
What concepts are involved with the scientific method?
Hypotheses, theory, laws, and models
How many truths are “self evident”?
6
What does “self evident” truth mean?
These are the assumptions of the whole scientific community about the natural world. They are incredibly logical theories that are accepted as “truth.”
List the six self evident truths:
- Existence
- Causality
- Position symmetry
- Time symmetry
- Non-Contradiction
- Occam’s razor
What is the existence assumption?
There exists a physical world separate and distinct from our minds that is comprehensible through our senses. This world is governed by the “laws of nature.”
What is the causality assumption?
Cause must always precede the effect.
Events in the physical world have natural causes that can be explained in terms of the laws of nature.
What is the position symmetry assumption?
That the laws of nature will act exactly the same anywhere in the universe.
What is the time symmetry assumption?
That the laws of nature have remained the same through time and will not change.
What is the non-contradiction assumption?
If there are two contradictory propositions, at least one of them must be false.
Both cannot be true. It’s possible neither of them are true.
What is the Occam’s razor assumption?
If there are alternative explanations of any phenomenon, that are all logical and explain the phenomenon equally well, the simplest explanation will be chosen.
Simple is better.
How many interactive forces do we know of in the universe?
Four
What are the interactive forces we know of?
- Strong force (or nuclear strong force)
- Electromagnetic force
- Weak force (or nuclear weak force)
- Gravity
What is a force?
A push or a pull.
What is the strongest force we know of?
Nuclear strong force
What is the weakest force we know of?
Gravity
When is the strong force strong?
When it is interacting with things smaller than the size of an atom.
What is the strongest force at atom level?
Electromagnetic
Which force dominates the world that we live in?
Electromagnetic
At what scale does gravity dominate?
Planets and solar systems (or larger)
What are atomic nuclei composed of?
Nucleons
What are nucleons?
Protons and neutrons
What are protons and neutrons made of?
Quarks
What is an atomic nuclei?
The positively charged central region of an atom.
What is a proton?
A positively charged particle in an atomic nuclei.
Made of 3 quarks.
What is a neutron?
An uncharged particle in an atomic nuclei.
Made of 3 quarks.
What does it mean if an atom is radioactive?
It means the nuclei is susceptible to being changed or broken apart from the weak force.
They can change spontaneously.
How does the electromagnetic force act on atomic nuclei?
It acts as a repulsion between protons (which are all positively charged, think of magnets).
Why do nuclei not explode apart due to the electromagnetic force?
Because the strong nuclear force is still more powerful at that distance, and it holds them together.
What surround atomic nuclei?
Electrons
What is an electron?
A particle in an atom (NOT the nuclei) that has a negative charge.
These are located outside of the nuclei inside an atom.
What is an atom?
The fundamental unit of an element.
What is an element?
A substance composed of the same number of protons in their nuclei.
What is a molecule?
The tiniest particles of a substance that retain all the physical properties of that substance, made up of more than one atom.
What does the left hand number mean on the periodic table?
How many protons the element has.
What force creates molecules from atoms?
Electromagnetic