Physics S1 Flashcards
theories
an explanation of phenomena that has only supporting evidence
observations
Empirical data collected through the senses, measurements or instruments to describe a phenomenon.
model
A simplified representation of a real-world system used to understand, predict, or simulate its behavior.
law
A concise statement that describes a fundamental relationship or principle in nature, often based on repeated observations and experiments.
measurements
Quantitative data obtained by comparing an unknown quantity to a standard unit using appropriate instruments.
uncertainty
The degree of doubt or imprecision associated with a measurement, typically expressed as a margin of error.
significant figures
The digits in a measurement that contribute to its precision and accuracy, excluding leading zeros.
unit
A standardized quantity used as a reference for measurements, such as meters for length or seconds for time.
Système International (SI)
The modern metric system of units used worldwide for scientific and everyday measurements.
meter
The SI unit of length, originally defined as one ten-millionth of the distance from the equator to the North Pole. The current definition is based off of the speed of light
kilogram
: The SI unit of mass, defined as the mass of the International Prototype of the Kilogram.
second
The SI unit of time, defined as the duration of 9,192,631,770 periods of radiation corresponding to the transition between two energy levels of the cesium-133 atom.
conversion factors
Ratios used to convert between different units of measurement, facilitating comparisons and calculations.
order-of-magnitude
A rough estimate of a quantity’s size or scale, typically expressed as a power of ten, used for quick assessments and approximations in science and engineering.
estimates
Approximate calculations or values used to make quick assessments or predictions, often based on simplified assumptions.
dimensions
The fundamental aspects or properties of a physical quantity, such as length, mass, and time, used in dimensional analysis.
dimensional analysis
A mathematical technique that involves checking the dimensions (units) of physical quantities to ensure that equations and formulas are consistent and accurate.
Kinematics
The branch of physics that deals with the motion of objects without considering the causes of motion (forces).
reference frame
A coordinate system or perspective used to describe the motion of an object, often with respect to a fixed point or observer.
displacement
The change in an object’s position or location, often measured as the straight-line distance and direction from the initial to the final position.
Average speed
The total distance traveled divided by the total time taken, representing the overall rate of motion.
elapsed time
The total duration or time interval between two specific events or points in time.
average velocity
The displacement divided by the elapsed time, indicating both the rate of motion and direction.
instantaneous velocity
The velocity of an object at a particular instant, typically the derivative of displacement with respect to time.
average acceleration
The change in velocity divided by the elapsed time, representing how quickly an object’s velocity is changing.
Instantaneous acceleration
The acceleration of an object at a specific moment in time, often described as the derivative of velocity with respect to time.
constant acceleration
A situation where an object’s acceleration remains unchanged over a given period, allowing for simplified kinematic calculations.
slope
The ratio of the vertical change (rise) to the horizontal change (run) between two points on a graph, representing the rate of change.
acceleration due to gravity
The constant rate at which objects near the Earth’s surface accelerate towards it, approximately 9.81 m/s².
vector
A physical quantity that has both magnitude and direction, such as velocity or force.
scalar
A physical quantity that has only magnitude, not direction, such as speed or temperature.
resultant vector
A single vector that represents the net effect of multiple vectors acting simultaneously, often found using vector addition.
components
The individual vectors that, when added together, yield a resultant vector, typically along perpendicular axes (e.g., horizontal and vertical components).
Projectile motion
The curved path followed by an object in motion near the Earth’s surface under the influence of gravity, where the only force acting is gravity.
relative velocity
The velocity of one object as observed from the perspective of another object in motion, taking into account both objects’ velocities and directions of motion.
Newton’s three law of motion
Three fundamental principles describing the relationship between forces and the motion of objects.
Newton’s first law (the law of inertia)
An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an external force.
Newton’s second law
The acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass (F = ma).
Newton’s third law
For every action, there is an equal and opposite reaction, meaning that the forces two objects exert on each other are equal in magnitude and opposite in direction.
inertia
The tendency of an object to resist changes in its state of motion.
mass
A measure of the amount of matter in an object, typically measured in kilograms (kg).
weight
The force exerted on an object due to gravity, calculated as the mass of the object multiplied by the acceleration due to gravity (W = mg).
gravitational force
The attractive force between two masses, described by Newton’s law of universal gravitation.
force
A push or pull that can cause an object to accelerate, measured in newtons (N).
net force
The vector sum of all the forces acting on an object, determining its acceleration.
normal force
The perpendicular force exerted by a surface to support the weight of an object resting on it
kinetic friction
The frictional force opposing the motion of an object when it is already in motion.
static friction
The frictional force resisting the initiation of motion when an object is at rest.
free-body diagram
A visual representation used to analyze forces acting on an object, often simplifying complex problems by isolating individual forces.
uniform circular motion
The motion of an object moving in a circle at a constant speed.
radial acceleration
The acceleration directed toward the center of a circular path, affecting objects in uniform circular motion.
centripetal acceleration
The acceleration of an object moving in a circle, always directed toward the center of the circle.
law of universal gravitation
A fundamental law stating that every mass attracts every other mass in the universe with a force proportional to the product of their masses and inversely proportional to the square of the distance between them.
Kepler’s laws
Three laws describing the motion of planets in elliptical orbits, formulated by Johannes Kepler.
Energy
The ability to do work or cause a change, often categorized as kinetic energy, potential energy, and other forms.
joules
The SI unit of energy, equivalent to one newton-meter (J).
Kinetic energy
The energy an object possesses due to its motion, calculated as 1/2 times the mass times the velocity squared (KE = 1/2 mv²).
translational kinetic energy
Kinetic energy associated with the linear motion of an object.
work-energy principle
The principle that the work done on an object is equal to the change in its kinetic energy.
Potential energy
The energy stored in an object due to its position or configuration, such as gravitational potential energy (GPE = mgh) or elastic potential energy (PE = 1/2 kx²).
spring stiffness constant
A measure of the stiffness of a spring, denoted as ‘k’ in Hooke’s Law, which relates the force exerted by a spring to its displacement.
conservative forces
Forces that do work on an object, where the work done depends only on the initial and final positions and is independent of the path taken.
Nonconservative forces
Forces that do work on an object, where the work done depends on the path taken and not just the initial and final positions.
law of conservation of energy
The fundamental principle stating that the total mechanical energy (sum of kinetic and potential energy) of an isolated system remains constant unless acted upon by external forces.
total mechanical energy
The sum of an object’s kinetic and potential energies in a closed system, which remains constant in the absence of external forces.
