Unit 1 Force and motion done No need for antimatter, accelerators Flashcards
Prefixes
An indicator of a fixed unit.
The base unit of Length: Meter
Prefixes: (Given in the exam)
Centi:10^-2
Milli:10^-3 Kilo:10^3
micro:10^-6 Mega:10^6
nano:10^-9 Giga:10^9
To turn a number into a specific prefix you multiply the base unit of your system with the 10 with its power
For example: 0.005 meters in millimeters, you’d multiply 0.005 m by 10^-3 = 0.000005 milli
Common base units:
Length: Meter
Mass: Gram
Volume: Liters
Time: Seconds
Force: Newtons
Energy: Joules
Solid sphere and plum pudding model
Solid sphere model: Was proposed by John Dalton circa the 1800s.
He stated that every material has a specific type of atom.
Created the name atom from the Greek word atomos which means the indivisible.
Plum pudding model: was proposed by J.J. Thomas circa the 1900s.
He states that the atom is positive with small negative charges in it.
Nuclear and Planetary model.
Nuclear model: Proposed by Ernest Rutherford in 1911.
He stated that there is a positively charged nucleus in the center of an atom with electrons orbiting around the nucleus.
Planetary model: Proposed by Bohr in 1913.
He states that electrons only exist in specific orbits/shells. and when an e- gains energy it moves to a higher energy level (called excited e-) this will be temporary and when the e- loses this energy it is called
(de-excitation).
Quantum model
Proposed by Erwin Schrodinger in 1926. He stated that it is impossible to know where the e- was exactly but it is a matter of possibilities like everything in quantum physics.
These places that e- can be in are called orbitals. (no more orbits).
more likely the e- will be closer to the nucleas with less energy.
nuetrons and protons are bigger than e-.
most of the atom is empty space.
the nucleus is very small compared to it’s orbitals.
e- are neither a wave or a particale.
Quarks
Subatomic particles carrying fraction electrons.
up charm top =2/3e-
down strange bottom = -1/3e-
building blocks of protons and neutrons (groups of 2 or 3)
proton= 2 up and 1 down quarks
nuetron= 1 up and 2 down quarks
Mass vs weight
weight: the attraction applied by earth to everything around it in order to absorb it. weight=mass*9.81(earth gravitational force)
mass= amount of matter in a body.
Distance vs Displacement and Speed vs Velocity
Distance: Total lenght covered =Time*Speed (speed without direction)
Diplacement=Shortest path btw 2 points(always straight line) =Time*Velocity (speed to a direction)
Average velocity or speed btw 2 point
(D2-D1)/(T2-T1)
Newtons 3 laws of motion
1) An object at rest stays at rest, and an object in motion stays in motion with the same speed and direction unless unbalanced force acts upon it.
2) Force(Jules) = Mass(Kg)*Acceleration(m/s)
F=ma
3) Every action (force) has an equal and opposite reaction.
Force types
there are 4 main types:
1)Gravity Attracts objects with mass toward each other. (it is a force according to newton). it is a very weak force compared to others.
2)Electromagnetic: Acts between charged particles (positive and negative charges). Ex: friction, electric, magnetic, drag, apthrust….
Weak nuclear force: Transformation of one type of a subatomic particle into another.
strong nuclear force: Force btw quarks.
these are also categorized into contact forces and non contact forces.
Forces effect
Deformation(change in shape or size) , changing speed, changing direction, inertia
Antimatter
Same as matter but with opposite electric charge e+ positron.
Proton- antiproton
Every kind of matter particle has an antimatter counterpart.
When the same anti matter and matter contact a big collision will happen lifting nothing else.
Accelerators
A machine that accelerate elementary particles in a speed of 99.9% of light speed. And then make them smash into something.
One of the experiments that proves relativity is muon lifetime experiment where muons(subatomic particles with a lifetime of 2.2microseconds when at rest).
Due to their relativistic speeds some of the muon created in the upper atmosphere reaches the earth’s surface and are detectable. If relativity is’t in count they won’t be able to survive until they reach the earth.
Basically their lifetime increase(time passes slower compared to us)
Inertia
Resistance to a change in velocity.
If a coin is placed above a card which is above a glass of water. If the card is pulled with velocity enough the coin won’t have enough time to react and it stays at rest and falls into the water because the friction force will be low and won’t be enough to move it, this is because of inertia .
Einstein:”Nothing happens until something moves”
Energy and energy transfer and transformation
Energy is the ability to do work
It can neither be created, nor destroyed, but can be transformed from one form to another. Law of conservation of energy.
Ex: chemical, mechanical, sound, light, or magnetic.
Potential and kinetic are types of mechanical energies.
Energy transfer refers to the movement of energy from one object or system to another. For example, when you kick a soccer ball, you transfer kinetic energy from your leg to the ball, causing it to move.
Mechanically - By the action of a force.
Energy transfer ways:
Electrically - By an electrical current.
By radiation - By Light waves or Sound waves.
By heating - By conduction, convection, or radiation.
Energy transformation occurs when energy changes from one form to another. For instance, when you turn on a lamp, electrical energy is transformed into light energy and thermal energy (heat). Similarly, when you eat food, your body transforms chemical energy stored in the food into kinetic energy for movement, thermal energy to maintain body temperature, and other forms of energy.
Object Freefalling through a fluid
Freefalling object initially accelerate due to gravity, but friction (/air resistance) Increases with speed until the forces are balanced (resultant force = 0 N).
Then, the object is falling at its terminal velocity. (السرعة النهائية)
