Physics Chapters 1-8 Flashcards

Questions and Answers

What is motion due to?

the nature of object or some sustained force

What is a hypothesis?

an educated guess; a reasonable explanation of an observation or experimental result that is not fully accepted as factual until tested over and over again by experiment

What is a law in physics?

a general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted; also known as principle

What constitutes a fact in science?

a phenomenon about which competent observers who have made a series of observations are in agreement Signup and view all the answers

What does pseudoscience refer to?

fake science that pretends to be a real science Signup and view all the answers

What is the scientific method?

principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, collection of data through observation and experiment, and formulation and testing of hypotheses Signup and view all the answers

What defines a theory in science?

a synthesis of a large body of information that encompasses well-tested and verified hypotheses about certain aspects of the natural world Signup and view all the answers

What is Newton's first law of motion?

the law of inertia; every object continues in its state of rest or of uniform motion in a straight line unless compelled to change that state by forces impressed upon it Signup and view all the answers

What is inertia?

the property of things to resist changes in motion Signup and view all the answers

What is a force?

in the simplest sense, a push or a pull Signup and view all the answers

What does net force refer to?

the vector sum of forces that act on an object Signup and view all the answers

What is mechanical equilibrium?

the state of an object or system of objects for which there are no changes in motion Signup and view all the answers

What is the equilibrium rule?

for any object or system of objects in equilibrium, the sum of the forces acting equals zero; in equation form, ∑F=0 Signup and view all the answers

What is speed?

how fast something moves; the distance traveled per unit of time Signup and view all the answers

What is velocity?

the speed of an object, with a specification of its direction of motion Signup and view all the answers

What is a vector quantity?

quantity in physics that has both magnitude and direction Signup and view all the answers

What is acceleration?

the rate at which velocity changes with time; the change in velocity may be in magnitude, direction, or both Signup and view all the answers

What does free fall mean?

motion under the influence of gravity only Signup and view all the answers

What is friction?

the resistive force that opposes the motion Signup and view all the answers

What is mass?

the quantity of matter in an object Signup and view all the answers

What is weight?

the force due to matter on an object Signup and view all the answers

What is a kilogram?

the fundamental SI unit of mass Signup and view all the answers

What is a Newton?

the SI unit of force Signup and view all the answers

What is volume?

the quantity of space an object occupies Signup and view all the answers

What does Newton's second law state?

the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object Signup and view all the answers

What is terminal speed?

the speed at which the acceleration of a falling object terminates because air resistance balances its weight Signup and view all the answers

What is momentum?

the product of the mass of an object and its velocity Signup and view all the answers

What is impulse?

the product of the force acting on an object and the time during which it acts Signup and view all the answers

What is the relationship of impulse and momentum?

impulse = the change in momentum of the object that the impulse acts upon; Ft = Δmv Signup and view all the answers

What is the law of conservation of momentum?

in the balance of an external force, the momentum of a system remains unchanged; hence, the momentum before an event involving only external forces is equal to the momentum after the event; mv(before event) = mv(after event) Signup and view all the answers

What is an inelastic collision?

a collision in which the colliding objects become distorted, generate heat, and possibly stick together Signup and view all the answers

What is an elastic collision?

a collision in which colliding objects rebound without lasting deformation or the generation of heat Signup and view all the answers

What does the work formula represent?

W = Fd Signup and view all the answers

What is power in physics?

the time rate of work; power = work/time Signup and view all the answers

What is energy?

the property of a system that enables it to do work Signup and view all the answers

What is mechanical energy?

energy due to the position of something or the movement of something Signup and view all the answers

What is potential energy?

the energy that something possesses because of its position Signup and view all the answers

What is kinetic energy?

energy of motion, quantified by the relationship KE = ½mv² Signup and view all the answers

What does the work-energy theorem state?

Work = ΔKE Signup and view all the answers

What is the conservation of energy?

energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes Signup and view all the answers

What defines a machine in physics?

a device, such as a lever or pulley, that increases or decreases a force or simply changes the direction of a force Signup and view all the answers

What is the conservation of energy for machines?

the work output of any machine cannot exceed the work input; in an ideal machine, where no energy is transformed into thermal energy, work(input) = work(output); (Fd)output = (Fd)input Signup and view all the answers

What is a lever?

simple machine consisting of a rigid rod pivoted at a fixed point called the fulcrum Signup and view all the answers

What is efficiency in machines?

the percentage of the work put into a machine that is converted into useful work output Signup and view all the answers

What is tangential speed?

the linear speed tangent to a curved path, such as in a circular motion Signup and view all the answers

What is rotational speed?

the number of rotations or revolutions per unit of time; often measured in rotations or revolutions per second or per minute Signup and view all the answers

What is rotational inertia?

that property of an object that measures its resistance to any change in its state of rotation Signup and view all the answers

Torque = _____ x force

lever arm Signup and view all the answers

What is the center of mass (CM)?

the average position of the mass of an object Signup and view all the answers

What is the center of gravity (CG)?

the average position of weight or the single point associated with an object where the force of gravity can be associated to act Signup and view all the answers

What is equilibrium?

the state of an object in which it is not acted upon by a force or a net torque Signup and view all the answers

What is centrifugal force?

an outward force apparent in a rotating frame of reference Signup and view all the answers

What is angular momentum?

the product of a body's rotational inertia and rotational velocity about a perpendicular axis Signup and view all the answers

What does conservation of angular momentum state?

when no external torque acts on an object or system of objects, no change of angular momentum can occur Signup and view all the answers

Study Notes

Fundamental Concepts of Physics

Motion occurs due to the nature of an object or an external sustained force.
A hypothesis provides a reasonable explanation for observations, pending further testing.
A law represents a tested hypothesis about natural quantities that has never been contradicted, also referred to as a principle.
A fact is a phenomenon supported by consensus among competent observers after extensive validation.
Pseudoscience misrepresents itself as science, lacking empirical support.

Scientific Approach

The scientific method is a systematic process for knowledge acquisition, involving problem recognition, data collection, and hypothesis formulation/testing.
A theory synthesizes verified hypotheses and information about specific aspects of the natural world.

Newton's Laws and Motion

Newton's first law (law of inertia) states that an object remains at rest or in uniform motion unless acted upon by an external force.
Inertia is an object's resistance to changes in motion.
Force is defined as a push or pull that can cause acceleration.
Net force is the vector sum of all forces acting on an object.

Equilibrium and Forces

Mechanical equilibrium describes a state where an object's motion remains unchanged; stationary objects stay at rest while moving objects maintain constant motion.
The equilibrium rule states that the sum of all forces in equilibrium equals zero (∑F=0).

Kinematics and Dynamics

Speed measures how fast something moves, while velocity includes speed and direction.
Vector quantities have both magnitude and direction, such as velocity and acceleration.
Acceleration describes the rate of change of velocity over time.

Gravitational Effects

Free fall refers to motion influenced solely by gravity.
Terminal speed is reached when the force of air resistance balances the weight of a falling object.

Mass and Weight

Mass quantifies the amount of matter in an object and is measured in kilograms.
Weight is the gravitational force exerted on an object.

Laws of Motion

Newton's second law shows the relationship between force, mass, and acceleration (F=ma).
Impulse is the product of force and the duration it acts, leading to changes in momentum.
The law of conservation of momentum indicates momentum remains unchanged in the absence of external forces.

Collisions

Inelastic collisions involve distortion and heat generation, while elastic collisions maintain shape and conserve kinetic energy.

Work and Energy

Work (W) is calculated as the product of force (F) and distance (d).
Power represents the rate at which work is done, expressed as work over time.
Energy is the system's capacity to perform work; it exists in various forms, including mechanical energy and kinetic energy (KE=½mv²).

Conservation Principles

The work-energy theorem states that work done on an object results in a change in its kinetic energy (Work = ΔKE).
The conservation of energy principle asserts that energy cannot be created or destroyed, only transformed.

Machines and Efficiency

Machines alter forces, such as levers and pulleys, and their efficiency measures the proportion of useful work output compared to input.
The work output from a machine never exceeds its work input due to energy losses.

Rotational Dynamics

Tangential speed is the linear speed along a curved path, while rotational speed measures revolutions over time.
Rotational inertia quantifies resistance to changes in rotational state, and torque is calculated as the product of lever arm and force.

Center of Mass and Gravity

The center of mass (CM) represents the average position of an object's mass.
The center of gravity (CG) is where gravitational force can be considered to act on a body.

Angular Momentum

Angular momentum is determined by an object's rotational inertia and velocity.
The conservation of angular momentum states that in the absence of external torque, angular momentum remains constant.

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Test your knowledge of key concepts from Physics Chapters 1-8 with these flashcards. Each card presents important terms and their definitions that cover fundamental principles such as motion and laws of nature. Perfect for quick revision and deepening your understanding of physics.