12 - Physics Flashcards
This deck explores core concepts in physics, such as forces, motion, energy transformations, and atomic structure. These principles lay the groundwork for understanding more complex phenomena in other scientific fields.
Define:
motion
A body’s change in position with time.
Examples include a cheetah hunting for prey, a fast-moving train and a person walking in the park.
Identify:
The SI unit of distance.
meters
(m)
Distance is a scalar quantity and does not consider direction.
Explain:
The difference between distance and displacement.
- Distance refers to the total path covered.
- Displacement is the shortest path taken considering direction.
Distance is scalar; displacement is a vector quantity.
Define:
speed
The magnitude of the velocity of an object, expressed in units of meters per second (m/s) or length/time.
It is measured by the total distance covered by an object per unit time.
Define:
velocity
The displacement traversed by an object per unit time, expressed in meters per second (m/s).
It is a vector quantity that includes direction.
Explain:
How velocity differs from speed.
Velocity is speed with a specified direction.
Both have the same SI unit (m/s), but velocity is a vector quantity.
Identify:
The SI unit of speed.
Meters per second
(m/s)
Speed is a scalar quantity that describes how fast an object is moving.
Define:
acceleration
The change in velocity over time.
It is a vector quantity with an SI unit of m/s².
Explain:
The difference between scalar quantity and vector quantity.
- Scalar quantities have only magnitude (for example, distance and speed)
- Vector quantities have both magnitude and direction (for example, displacement, velocity and acceleration).
List:
Four types of motion.
- Translational
- Rotational
- Oscillatory
- Irregular
Describe:
translational motion
All parts of an object cover the same amount of distance at the same time.
Examples include a person walking or a moving car.
Describe:
rotational motion
- It refers to an object’s motion along an axis.
- Different parts of the rotating object move at varying speeds based on their distance from the axis.
Define:
Oscillatory or periodic motion
It is the repeated motion of objects at equal time intervals.
Examples include a pendulum, a swing or a vibrating tuning fork.
Describe:
irregular or random motion
It occurs when there is no observed pattern in an object’s motion.
Examples include the motion of insects, birds and dust particles.
Identify:
Newton’s first law of motion.
An object remains in its original state of motion unless acted upon by an unbalanced force.
This law emphasizes the concept of inertia.
Identify:
Newton’s second law of motion.
Acceleration is directly proportional to net force and inversely proportional to mass.
This relationship is expressed as Fnet = ma.
Identify:
Newton’s third law of motion.
In every action, there is an equal but opposite reaction.
For example, when pushing a table, the table pushes back with equal force.
Describe:
A free-body diagram
A graphical illustration showing all the forces acting on a body.
It is useful for analyzing problems involving motion and forces.
Identify:
The formula to calculate net force.
Fnet = ma
Where Fnet is the net force, m is mass and a is acceleration.
Identify:
What is the branch of physics that involves the study of motion?
mechanics
Define:
force
It is the push or pull resulting from an interaction between objects.
Forces are vector quantities, meaning they have both magnitude and direction.
Identify:
The formula for calculating speed.
speed = distance / time
This formula calculates the average speed of an object.
Identify:
The formula for calculating velocity.
velocity = displacement / time
This formula calculates the average velocity of an object.
Explain:
The difference between displacement and distance.
- Displacement is the vector sum of the paths taken.
- Distance is the total length of the path traveled.
Displacement can be zero even if the distance is not.
Explain:
If a person walks from point A to point B and back to A, what is the total displacement?
Zero meters
Displacement considers the initial and final positions, which are the same in this case.
Explain:
If a person walks 5 meters to point B and then 5 meters back to point A, what is the total distance covered?
10 meters
Distance is the total length of the path traveled, regardless of direction.
Explain:
What is the average speed if a person travels 14 km in 4 hours?
3.5 km/h
This speed calculation does not consider direction.
Explain:
What is the average velocity if a person has a total displacement of 12 km west in 3 hours?
4 km/h west
This velocity calculation retains direction in the result.
Define:
acceleration
It describes the change in velocity over time and is a vector quantity with both magnitude and direction.
Acceleration can be understood as the rate of change of velocity.
Identify:
The formula for Newton’s Second Law of motion
F = m * a
Where:
F is force
m is mass
a is acceleration
This law explains how forces acting on an object cause acceleration.
Explain:
What does negative acceleration indicate?
That an object is slowing down.
It refers to a decrease in the magnitude of velocity.
Identify:
The formula for calculating average acceleration
a_avg = (vf - vi) / (tf - ti) = Δv / Δt
This formula represents the change in velocity over the change in time.
Identify:
The components of acceleration in circular motion
It can have both tangential and centripetal components.
Tangential acceleration relates to changes in speed, while centripetal acceleration relates to changes in direction.
Define:
acceleration
Rate of change of velocity over time.
This definition highlights the relationship between acceleration and motion.
Explain:
How does acceleration affect velocity?
It causes changes in a velocity vector’s magnitude or direction.
This can include speeding up, slowing down or changing direction.
Define:
gravity
An invisible force that pulls objects towards itself.
It prevents objects on Earth from being flung into space.
It is a force of attraction between two objects, first defined by Sir Isaac Newton.
Identify:
The person credited with the first definition of gravity.
Sir Isaac Newton
Newton’s observations began with the falling of an apple from a tree.
Explain:
What did Galileo Galilei discover about falling objects?
All objects, regardless of mass, accelerate towards the Earth at the same rate.
He demonstrated this by dropping weights from the Leaning Tower of Pisa.
Identify:
The acceleration due to gravity on Earth.
9.81 meters per second squared
(9.81 m/s²)
This rate is consistent for all objects falling towards Earth.
Identify:
The shape scientists observed for the orbits of planets.
Elliptical
This understanding was facilitated by Newton’s discovery of gravity.
Identify:
The misconception about falling objects before Galileo’s discovery.
That objects with greater mass fall at a faster rate.
This idea was largely attributed to Aristotle.
Explain:
How does distance affect gravitational attraction between objects?
Closer objects exert a stronger gravitational pull.
Gravity weakens as objects get further apart.
Define:
weight
The non-contact force of Earth’s gravitational pull on an object.
Identify:
The equation used to calculate weight.
W = m * g
Weight is quantified by multiplying its mass by the gravitational acceleration force.
Identify:
The standard metric unit for weight.
Newtons
(N)
Explain:
How does the weight of an object on the moon compare to its weight on Earth?
The weight on the moon is 1/6 of its weight on Earth.
Identify:
The difference between mass and weight.
- Mass is the amount of matter in an object.
- Weight is the gravitational force exerted on an object.
Define:
mass
It is a scalar quantity that measures the amount of matter.
Explain:
What happens to the mass of an object as it moves to different locations?
It remains constant no matter the location.
Identify:
The 3 most commonly used units to measure mass.
- Kilograms (kg)
- Grams (g)
- Pounds (lbs)
Identify:
The formula to find the mass of an object given its volume and density.
m = d * V
Explain:
How do you convert mass to weight?
Multiply the mass by the gravitational force: W = m * g
List:
The characteristics of mass.
- Scalar quantity (magnitude only)
- Constant, does not change with location
- Cannot be zero
- Measured in Kilograms (kg), grams (g) and pounds (lbs)
List:
The characteristics of weight.
- Vector quantity (magnitude and direction)
- Changes with location due to gravitational fluctuations
- Can be zero in space (no gravity)
- Measured in Newtons (N)
Define:
static electricity
The build up of a temporary electric charge in an object. It is produced by pressure, heat, induction and the triboelectric effect.
Static electricity is stationary and is discharged when the charge moves.
Identify:
The difference between static electricity and current electricity.
Static electricity is stationary, while current electricity is moving.
Static electricity is a temporary charge, whereas current electricity flows continuously.
Identify:
The 3 basic subatomic particles that make up atoms.
- Protons
- Neutrons
- Electrons
Protons carry a positive charge, neutrons are neutral and electrons carry a negative charge.
Explain:
What happens when an atom gains electrons?
It becomes negatively charged.
Conversely, losing electrons causes the atom to become positively charged.
Identify:
A common example of static electricity.
lightning
Lightning is thought to result from the triboelectric effect within thunderstorm clouds.
Describe:
A Van de Graaff generator
It is a device that creates a static electric charge.
It uses a belt and rollers to induce charge through the triboelectric effect.
List:
3 uses of static electricity.
- Ink jet printers
- Car paint
- Pollution particulate collection
List:
3 methods that can help remove unwanted static electricity.
- Humidification
- Conducive bags
- Fabric softener
Define:
magnetism
A phenomena created by the movement of charged particles.
Magnetism involves protons and electrons, where moving electrons create an electric current and a magnetic field.
List:
3 main types of magnets.
- Permanent magnets
- Temporary magnets
- Electromagnets
Each type has unique properties and ways of being created.
Explain:
What causes magnetism?
Alignment of charged particles within a material, creating a net external charge.
Charge alignment can result from physical separation or electron orientation.
Define:
The poles of a magnet
The oppositely charged sides created by the physical separation of charges.
The negative side is called the south pole, and the positive side is called the north pole.
Oppositely charged magnetic poles attract, while like-charged magnetic poles repel.
Define:
magnetic dipole
A magnetic object with one side having a net negative charge and the other a net positive charge.
All magnets are dipoles and cutting a dipole creates two new dipoles.
Define:
magnetic monopole
An object that has only a single charge, such as an electron or proton.
No one has been able to separate the poles of a magnetic dipole.
List:
Some examples of magnetism in daily life.
- Compass needle
- MRI machines
- Magnetic cabinet latches
- Electronic storage devices
An MRI is a large magnet that temporarily realigns the dipole water molecules in a person placed within it.
Explain:
The importance of magnetism.
It is responsible for much of today’s technology due to its relationship with moving charged particles and electric fields.
Understanding magnetism is crucial for advancements in various technological fields.
Define:
light
It is a form of electromagnetic (em) radiation.
Electromagnetic radiation is categorized using the electromagnetic spectrum.
Identify:
The frequency range of visible light.
400 THz to 700 THz
Define:
Terahertz
(THz)
A unit of frequency equal to one trillion hertz.
A hertz is the number of oscillations or cycles that occur in one second.
Identify:
How does light travel?
As a wave.
Identify:
The equation relating speed of light, wavelength and frequency.
c = λf
where:
c = speed of light
λ = wavelength in meters
f = frequency in Hertz
List:
The seven pure spectral colors in order from lowest frequency to highest in the visible spectrum.
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet
Just outside of the visible range on the red end is the infrared range. Just outside on the violet end is the ultraviolet range.
Identify:
The highest frequency of light in the visible spectrum.
Violet light. It goes as high as 750 THz.
Fill in the blank:
White light is a combination of _______.
all colors of the spectrum
White light can be split up to form a spectrum using a prism.
Explain:
How do human eyes perceive color?
By detecting light in the visible range. Each frequency corresponds to a particular color.
Identify:
Some factors that influence the naming of colors.
- Personal experiences
- Languages
- Cultures
Identify:
The instrument capable of measuring the frequency of light.
A photometer.
The frequency of light is part of a formula that includes the light’s wavelength and its speed: f = c/w.
Define:
sound
Energy that travels as a vibration through molecules of matter (usually air).
Energy transfer through vibration can be shown by a periodic wave with defined properties.
Define:
Compressions and rarefactions in sound waves
When energy travels as a vibration, molecules vibrate back and forth. Compressions occur when molecules are close together; rarefactions when molecules are far apart.
These can be represented by a sine wave.
List:
The properties of sound waves.
- Wave direction
- Wavelength
- Frequency
- Wave speed
- Amplitude
- Timbre
Explain:
wave direction
Sound waves propagate outwards in all directions from the source.
The direction can be changed through reflection, like an echo.
Define:
wavelength
The measurable distance between two waves.
Wavelength is a key property of sound waves.
Define:
frequency
in the context of sound
The number of waves that pass by a certain point over a certain amount of time.
Higher frequency corresponds to shorter wavelengths.
Define:
wave speed
in sound
It is determined by how quickly energy is passed from molecule to molecule.
Sound travels at different speeds through different materials.
Define:
amplitude
The height of a sound wave measured from the rest position to the crest of the wave.
Taller waves correspond to louder sounds.
Define:
timbre
The perceived musical sound quality of a note.
Timbre differentiates music from noise.
Describe:
How do humans perceive sound?
Energy from the sound wave vibrates the eardrum and the brain processes it.
The perception is influenced by amplitude, wavelength, frequency, direction and timbre.
Explain:
The relationship between amplitude and sound.
Amplitude is directly related to the energy the sound wave carries. Higher amplitude means a louder sound.
Amplitude decreases over time.
Identify:
The SI unit used to measure amplitude.
Decibels
(dB)
Humans can hear sounds between 0 and 140 dB.
Explain:
The relationship between frequency and sound.
Frequency is directly related to the wavelength of the sound; shorter wavelengths mean higher frequency.
Frequency determines the pitch of a sound.
Explain:
The significance of a higher hertz measurement.
A higher hertz measurement indicates a faster traveling sound that is perceived as a higher-pitched sound.
For example, dog whistles can produce sounds up to 35,000 Hz.
Identify:
The unit used for measuring frequency.
Hertz
(Hz)
1 Hz equals one wave per second.
Identify:
What are the human hearing limits in terms of frequency?
Humans can hear sounds between 20 Hz and 20,000 Hz.
Other animals may have different hearing ranges.
Describe:
The Law of Conservation of Mass
Mass can neither be created nor destroyed.
Also called the law of conservation of matter.
Identify:
Who is credited with the modern formulation of the Law of Conservation of Mass?
Antoine Lavoisier
His work in the late 18th century was pivotal in establishing this law.
Explain:
The relationship between the law of conservation of matter and chemical reactions.
Atoms are not created or destroyed; they are rearranged.
Mass before and after a reaction remains equal.
Identify:
Processes that are exceptions to the law of conservation of matter.
Nuclear processes, including fusion, fission and matter-antimatter reactions.
In these cases, mass can be converted into energy.
List:
Some examples that illustrate the law of conservation of matter.
- Burning of wood
- Rainfall
- Burning of gasoline
- Rusting metal
Define:
energy
The ability to do work.
In this context, work is better understood as movement.
List:
The two main categories of energy.
- Kinetic energy
- Potential energy
Define:
kinetic energy
The energy of movement or motion.
Define:
potential energy
Energy that is stored and has the potential to move.
Identify:
Examples of kinetic energy.
- A ball rolling down a hill
- Dogs running
- Cars driving
- Soup being stirred in a pot
- A kite flying in the wind
- Airplanes flying
- Water rushing down a waterfall
Identify:
Examples of potential energy.
- A ball at the top of a swing
- A car stopped at the top of a hill
- Dishes in the cupboard
- Clothes in the dresser
- Dirt on the ground
- A bow pulled taut before firing an arrow
- A rock at the edge of a cliff
- Books on a shelf
- A container of flour in the pantry
- Clothes in your dresser
Explain:
The main difference between kinetic and potential energy.
- Kinetic energy involves motion.
- Potential energy is stored and not moving.
Can kinetic energy be converted to potential energy?
Yes, when a moving object reaches a height and stops.
Define:
conductor
Material that transfers heat well.
Examples include metals like those used in pots and pans.
Define:
insulator
Material that does not transfer heat well.
Examples include air, wood, and glass.
Define:
conduction
Heat transfer through direct contact.
It occurs when hot particles vibrate and transfer energy to neighboring particles.
Explain:
How does convection transfer heat?
Through the movement of fluids (liquids and gases).
It often starts with conduction and continues as the fluid moves.
Define:
radiation
Heat transfer through electromagnetic waves.
It can occur without a medium, such as the sun warming the Earth.
Explain:
What does black surface do with radiant energy?
It absorbs and emits energy easily.
This is why blacktop gets hot in the sun.
Explain:
What happens to water during convection heating?
Hot water becomes less dense and rises.
Colder, denser water sinks to take its place, creating a cycle.
List:
The three methods of heat transfer.
- Conduction
- Convection
- Radiation
Each method has distinct mechanisms for transferring heat.
List:
The four states of matter.
- Solid
- Liquid
- Gas
- Plasma
Each state has distinct properties related to shape and volume.
List:
Some common characteristics of solids.
- Definite shape and volume
- Immobile molecules
- Stillness
- Maintain their own shape
Identify:
An example of a solid state of matter.
Ice
Other examples include bricks and gold.
List:
Some common characteristics of liquids.
- Moderate energy
- Mobile atoms/molecule
- Movement (fluid)
- Moderate density
- Definite volume
- Indefinite shape (assume shape of container)
Identify:
An example of a liquid state of matter.
water
Mercury is another example.
Identify:
Some common characteristics of gases.
- Lowest density among three main states
- Quickly moving molecules
- High internal energy level
- Indefinite volume and shape
- Fluid
Mention:
An example of a gas state of matter.
Helium
Air and hydrogen are also examples.
Define:
plasma
A gas-like state of matter with high energy and free-floating electrons.
It is the most common state of matter in the universe.
Identify:
An example of plasma.
The Sun
Lightning is also a natural example.
Identify:
Phase transitions between the three states of matter.
Solid to liquid (melting), liquid to gas (evaporation), gas to liquid (condensation), liquid to solid (freezing), solid to gas (sublimation) and gas to solid (deposition).
Define:
recombination
Process by which plasma changes to gas.
Also called deionization.
This process is less commonly observed in daily life.
Define:
ionization
Process by which gas changes to plasma.
