Name: centripetal acceleration in circular motion
Uploaded: 2023-04-30T10:52:21.000Z
Duration: 1 min 14 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Earth and Environmental Science

Earth's Place in the Universe

ESS.EES.1.2

Uniform Circular Motion

On dit qu’un objet se déplaçant le long d’une trajectoire circulaire présente un mouvement circulaire, qui peut être uniforme ou non. Dans un mouvement circulaire uniforme, l’objet se déplace à une vitesse constante.
Pour un satellite en orbite, la force gravitationnelle de la Terre fournit la force centripète nécessaire au mouvement circulaire.
À tout instant, la vitesse linéaire du satellite est tangente à la trajectoire circulaire, de sorte que sa magnitude reste constante, mais sa direction varie.
Comme la direction de la vitesse change, le satellite accélère radialement vers l’intérieur à tout instant. Cette accélération est appelée accélération centripète ou accélération radiale.
En divisant l'équation de la force par m, l'intensité de l'accélération centripète est le carré de la vitesse divisé par la distance du satellite par rapport au centre de la Terre.
Comme la vitesse est égale à la circonférence orbitale, 2πr, divisée par la période T, on obtient une relation entre l’accélération centripète et la période de temps du satellite.

mouvement circulaire uniforme

Le mouvement circulaire uniforme est un type spécifique de mouvement dans lequel un objet se déplace sur un cercle avec une vitesse constante. Par exemple, n'importe quel point sur une hélice qui tourne à une vitesse constante subit un mouvement circulaire uniforme. Les aiguilles des secondes, des minutes et des heures d'une montre subissent également un mouvement circulaire uniforme. Il est difficile de croire que les points sur ces objets en rotation accélèrent réellement, même si la vitesse de rotation est constante. Pour comprendre cela, nous devons analyser le mouvement en termes de vecteurs.

En cinématique unidimensionnelle, les objets avec une vitesse constante ont une accélération nulle. Cependant, en cinématique bidimensionnelle et tridimensionnelle, même si la vitesse est constante, une particule peut avoir une accélération si elle se déplace le long d'une trajectoire courbe, telle qu'un cercle. La direction du vecteur d'accélération est dirigée vers le centre du cercle. Il s'agit d'une accélération radiale et on l'appelle l'accélération centripète. Le mot centripète vient des mots latins « centrum » signifiant « centre » et « petere » signifiant « chercher », et prend donc le sens de « recherche du centre ». L'accélération centripète peut avoir une large gamme de valeurs, en fonction de la vitesse et du rayon de courbure du chemin circulaire.

Ce texte est adapté de <a href="https://openstax.org/books/university-physics-volume-1/pages/4-4-uniform-circular-motion">Openstax, University Physics Volume 1, Section 4.4: Uniform Circular Motion.</a>

Mouvement circulaire uniforme

Le mouvement circulaire uniforme est un type spécifique de mouvement dans lequel un objet se déplace dans un cercle à vitesse constante. Par exemple, n’importe quel point sur une hélice...

Education

Enseignement

JoVE Core

Physics

Physique

Unit 1

Unité 1

Motion in Two or Three Dimensions

Mouvement en deux ou trois dimensions

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

centripetal acceleration in circular motion

Uniform circular motion describes motion in a circle at constant speed. An object follows a curved path, but its speed does not change. The motion of a point on a propeller spinning at a steady rate and the second, minute, and hour hands of a watch are common examples.

Even with constant speed, these objects are still accelerating. That idea can seem surprising because in one-dimensional motion, constant speed means zero acceleration. In two- and three-dimensional motion, a particle can accelerate if it moves along a curved path such as a circle.

To understand this motion, the direction of the velocity and acceleration vectors matters. The acceleration points toward the center of the circle. This radial acceleration is called centripetal acceleration, and the term means “center seeking.”

Centripetal acceleration can vary over a wide range. Its value depends on the speed of the object and the radius of the circular path. A faster motion or a tighter curve changes the size of the acceleration.

Centripetal Acceleration in Circular Motion

centripetal-acceleration-in-circular-motion

position and displacement vectors

Describing Motion with Position Changes

Describing motion starts with position. Position tells where an object is at a particular time. It must be measured relative to a frame of reference, which is an arbitrary set of axes used to describe position and motion. Earth is often used as a frame of reference. It helps describe an object’s location in relation to stationary objects on Earth. Many important motions also take place in two dimensions, or in a plane. In those cases, position, velocity, and acceleration can each be described...

average and instantaneous velocity vectors

average-and-instantaneous-velocity-vectors

Position Change and Instant Velocity

Position change and instant velocity are key ideas in kinematics. To describe motion, time must be included. Time tells us where an object is and how fast it is moving. The speed of an object comes from how its position changes with time. Each position is tied to a specific time. When the details of motion at each instant are not important, the rate is given as average velocity. Average velocity is a vector. It equals the total displacement between two points divided by the elapsed time. Real...

acceleration vectors

How Velocity Changes Create Acceleration

Acceleration describes how velocity changes over time. In physics, acceleration is a vector, which means it has both size and direction. It points in the same direction as the change in velocity, written as Δv. The larger the acceleration, the larger the change in velocity over a given time. Because velocity is a vector, it can change in more than one way. An object can speed up, slow down, change direction, or do both at once. A runner traveling 10 km/h due east who stops, turns around, and...

direction of acceleration vectors

Negative Acceleration and Motion Reversal

Acceleration describes a change in velocity. That change can be a change in speed, a change in direction, or both. The acceleration vector points in the direction of the velocity change, not always in the direction the object is moving. When an object slows down, its acceleration points opposite to its motion. This is often called deceleration. The term can be confusing in physics because deceleration is not a vector. It does not give a direction relative to a coordinate system, so the correct...

projectile motion

Projectile Paths Under Gravity

Projectile motion describes the path of an object thrown into the air under Earth’s gravity. The object is called a projectile, and its curved path is called the trajectory. This motion appears in many real situations, such as fireworks, a golf ball in flight, meteors entering Earth’s atmosphere, and bullets being fired. When a falling object has no horizontal movement, it is described as one-dimensional projectile motion. When motion includes both horizontal and vertical parts, it is...

/files/media/science-education/science-education-thumbs/12634.jpg

projectile motion: equations

Solving Projectile Motion with Components

Projectile motion can be solved by breaking the motion into horizontal and vertical components. This approach is used for common examples like a basketball throw, an arrow shot from a bow, and kids jumping into a pool. The motion is then analyzed along the x-axis and y-axis. Start by separating displacement into x and y parts. The horizontal and vertical parts of velocity are also separated. If the projectile has speed v and direction θ relative to the horizontal, the vertical component is...

projectile motion: example

Projectile Motion in Sports and Orbit

Projectile motion helps explain both sports throws and motion near Earth. A javelin thrower uses this idea to send the javelin as far as possible. The thrower also takes a short run-up to increase the initial speed of the javelin. For a projectile on level ground, the range is the horizontal distance it travels. The range is largest at a 45° angle, so javelin throwers try to release the javelin as close to that angle as possible. In this case, the range equation assumes the distance is very...

uniform circular motion

Uniform circular motion describes motion in a circle at constant speed. An object follows a curved path, but its speed does not change. The motion of a point on a propeller spinning at a steady rate and the second, minute, and hour hands of a watch are common examples. Even with constant speed, these objects are still accelerating. That idea can seem surprising because in one-dimensional motion, constant speed means zero acceleration. In two- and three-dimensional motion, a particle can...

non-uniform circular motion

Circular Motion with Changing Speed

Circular motion can happen with changing speed. In this case, the object still follows a circular path, but it may speed up or slow down as it moves. When speed changes during circular motion, the motion is called non-uniform circular motion. This adds tangential acceleration, which points along the path of motion and shows a change in speed. Centripetal acceleration is still present in circular motion. It describes the time rate of change of the direction of the velocity vector and points...

relative velocity in one dimension

Relative Motion in a Train and Earth

Relative motion depends on the reference frame used to measure velocity. A reference frame is the point of view from which motion is described. In many examples, Earth is the reference frame. If someone is said to be sitting in a train moving east at 10 m/s, that speed is measured relative to Earth.

relative velocity in two dimensions

Adding Velocities Across Reference Frames

Relative velocity describes motion as measured from a chosen reference frame. It can also describe the motion of one reference frame compared with another. In two dimensions, this idea helps track how position and velocity change from frame to frame. Consider a particle P and two reference frames, S and S′. The position of the origin of S′, measured in S, and the position of P, measured in S′, can be combined with vector addition to find the position of P in S. This relation shows how motion...

key terms and concepts

Learn how constant-speed motion in a circle still involves acceleration, why the acceleration points inward, and how speed and radius affect centripetal acceleration.

Centripetal Acceleration in Circular Motion | JoVE K12

physics

JoVE Core Physique présente plusieurs branches de la physique fondamentale grâce à des vidéos animées concises et faciles à comprendre ; cela inclut: la cinématique, la dynamique, la mécanique des fluides, la mécanique statique, les ondes et l'acoustique. En parallèle, les vidéos de scientifiques à l'action démontrent l'application de concepts associés à ces domaines dans des expériences de recherche classiques et originales réalisées dans des laboratoires modernes du monde entier.

Texas Essential Knowledge and Skills

High School

PHYS.5

PHYS.5.D

Florida Department of Education

Physical Science

SC.912.P.12

SC.912.P.12.2

Georgia Standards of Excellence

SP2.

Circular Motion

Kepler's First Law of Planetary Motion

In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He ...

Kepler's Second Law of Planetary Motion

In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. His ...

Kepler's Third Law of Planetary Motion

In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. In ...

Detection of Black Holes

Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their ...

Tidal Forces

The origin of Earth&#39;s ocean tides has been a subject of continuous investigation for over 2000 years. However, the work of Newton is considered to be ...

circular-orbits-and-critical-velocity-for-satellites

Circular Orbits and Critical Velocity for Satellites

The Moon orbits around the Earth. In turn, the Earth (and other planets) orbit the Sun. The space directly above our atmosphere is filled with artificial ...

Gravity between Spherical Bodies

Newton&#39;s law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, ...

Use models to illustrate the formation of the solar system.

ESS.EES.1.1

Uniform circular motion is a specific type of motion in which an object travels in a circle with a constant speed. For example, any point on a propeller ...

Gyroscope: Precession

Precession can be demonstrated effectively through a spinning top. If a spinning top is placed on a flat surface near the surface of the Earth at a ...

simple-harmonic-motion-and-uniform-circular-motion

Simple Harmonic Motion and Uniform Circular Motion

While simple harmonic motion and uniform circular motion may be two separate concepts, they correlate and interlink with each other. Simple harmonic ...

Use mathematics and computational thinking to analyze Earth's motion through space.

Light as Energy

The energy required to carry out photosynthesis is light&#8212; typically electromagnetic radiation from the sun. The range of all possible wavelengths is ...

Nuclear Fusion

The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process ...

First Law of Thermodynamics

The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed. This can be demonstrated within a classic food web ...

Energy Dynamics

The Food Chain
Energy is one of the most important abiotic factors in an ecosystem and organisms in an ecosystem are connected by the flow of energy and ...

Use models to illustrate how the sun produces energy.

ESS.EES.1.3

Radiation: Applications

The average temperature of Earth is the subject of much current discussion. Earth is in radiative contact with both the Sun and dark space; it receives ...

What is Weather?

Overview

Weather refers to the current state of atmospheric conditions at a specific time and place. Weather is temporary and is influenced by the ...

What is Climate?

Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, &#8220;Climate is what you expect. ...

Radiation Pressure: Problem Solving

The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave&#39;s momentum ...

Absorption of Radiation

The rate of heat transfer by emitted radiation is described by the Stefan-Boltzmann law of radiation:

where &#963; is the Stefan-Boltzmann constant, a ...

Construct an explanation to infer how incoming solar radiation interacts with Earth systems to support life.

ESS.EES.1.4

Explain how Earth's position relative to the sun influences conditions on Earth.

Centripetal Acceleration in Circular Motion

Description

Transcript

Tags

More videos by Standards