6.2 Centripetal Acceleration

3 min readjune 18, 2024

is the key to understanding . It's the force that keeps objects moving in a curved path, like a car rounding a corner or a planet orbiting the sun.

This concept is crucial in physics, explaining everything from how separate materials to why roller coasters don't fly off the tracks. It's all about the balance between speed, , and the forces at play.

Centripetal Acceleration

Centripetal acceleration calculation

Top images from around the web for Centripetal acceleration calculation
Top images from around the web for Centripetal acceleration calculation
  • (aca_c) is the acceleration directed towards the center of a circular path caused by a centripetal force acting perpendicular to the direction of motion
  • Calculate centripetal acceleration using (vv) and radius (rr): ac=v2ra_c = \frac{v^2}{r}
    • Linear velocity is the speed of an object moving along the circular path (car on a curved road, satellite orbiting Earth)
    • Radius is the distance from the center of the circular path to the object (distance from the center of a roundabout to a car)
  • Calculate centripetal acceleration using (ω\omega) and radius (rr): ac=ω2ra_c = \omega^2r
    • is the rate of change of angular displacement over time, measured in radians per second (Earth's rotation, second hand on a clock)
    • Relationship between linear velocity and angular velocity: v=ωrv = \omega r

Centrifuges and material separation

  • Centrifuges are devices that use centripetal acceleration to separate materials based on their densities commonly used in medical and research laboratories (separating blood components, isolating DNA)
  • The rotates at high speeds, creating a strong centripetal acceleration
  • Denser materials experience a greater centripetal force and move towards the outer edge of the centrifuge (red blood cells, heavier sediments)
  • Less dense materials experience a weaker centripetal force and remain closer to the center (plasma, lighter liquids)
  • is the separation process used to isolate specific components from a mixture (separating cream from milk, purifying vaccines)

Effects of centripetal acceleration

  • Objects in circular motion constantly experience centripetal acceleration directed towards the center of the circular path
  • The magnitude of centripetal acceleration depends on the object's velocity and the radius of the circular path
  • Real-world examples of centripetal acceleration:
    1. A car making a turn experiences centripetal acceleration, enabling it to follow a curved path with between the tires and the road providing the necessary centripetal force
    2. Planets orbiting the sun experience centripetal acceleration due to the gravitational force acting as the centripetal force
    3. A roller coaster loop exerts centripetal acceleration on the passengers, keeping them in their seats as they travel through the circular path
  • If the centripetal force is insufficient or removed, the object will continue moving in a straight line tangent to the circular path ()
    • A spinning yo-yo will fly off in a straight line when the string breaks, as the centripetal force provided by the string is no longer present
    • A rider on a merry-go-round will be thrown off tangentially if they lose their grip on the handrail

Circular Motion and Forces

  • Circular motion occurs when an object moves in a circular path, constantly changing direction but maintaining a constant speed
  • is the instantaneous linear motion of an object moving in a circle, perpendicular to the radius at any given point
  • The is the perpendicular force exerted by a surface on an object in contact with it, which can contribute to centripetal force in some scenarios (e.g., a car on a banked turn)
  • Friction often provides the necessary centripetal force for objects to maintain circular motion on a flat surface (e.g., a car turning on a flat road)

Key Terms to Review (31)

Ac: ac, or alternating current, is the flow of electric charge that periodically reverses direction. This is in contrast to direct current (dc), where the flow of electric charge is unidirectional. ac is the standard form of electricity supplied to homes and businesses, and is the type of current used in most electronic devices and power grids.
Angular velocity: Angular velocity is the rate of change of the rotation angle with respect to time. It is usually measured in radians per second (rad/s).
Angular Velocity: Angular velocity is a measure of the rate of change of the angular position of an object rotating around a fixed axis or point. It describes the speed of rotational motion and is a vector quantity, indicating both the magnitude and direction of the rotation.
Banked Curve: A banked curve, also known as a superelevated curve, is a section of a road, railway, or racetrack that is designed with a tilted or inclined surface to counteract the centrifugal force experienced by vehicles or trains as they navigate the curve. This tilting of the curve helps to keep the vehicle stable and prevent it from sliding or losing control during the turn.
Centrifugation: Centrifugation is a separation technique that uses centripetal acceleration to separate particles or components of a mixture based on their size, shape, density, and other physical properties. It is a widely used method in various scientific fields, including biology, chemistry, and medicine.
Centrifuge: A centrifuge is a device that uses rotational motion to separate components of different densities within a mixture by applying centripetal force. It is commonly used in laboratories and industrial applications.
Centrifuges: Centrifuges are devices that utilize centripetal acceleration to separate substances of different densities. They are widely used in various scientific and industrial applications, including the purification and analysis of materials.
Centripetal acceleration: Centripetal acceleration is the acceleration experienced by an object moving in a circular path, directed towards the center of the circle. It is responsible for changing the direction of the object's velocity without altering its speed.
Centripetal Acceleration: Centripetal acceleration is the acceleration experienced by an object moving in a circular path, directed towards the center of the circular motion. It is the rate of change of the object's velocity vector, causing the object to constantly change direction and maintain its circular trajectory.
Circular Motion: Circular motion is the motion of an object in a circular path or orbit around a central point or axis. This type of motion is characterized by the object continuously changing direction while maintaining a constant distance from the center of the circle.
Conical Pendulum: A conical pendulum is a type of pendulum where the pendulum bob moves in a circular path around a central axis, forming a cone shape. The motion of the conical pendulum is governed by the balance between the centripetal force and the force of gravity, making it an important concept in the study of centripetal acceleration.
F = ma: F = ma is a fundamental equation in physics that describes the relationship between force (F), mass (m), and acceleration (a). It states that the force acting on an object is equal to the product of the object's mass and its acceleration. This equation is central to understanding the dynamics of objects in motion and is applicable in various contexts, including the topics of normal force, tension, and centripetal acceleration.
Friction: Friction is the resistive force that occurs when two surfaces interact, opposing the relative motion between them. It acts parallel to the surfaces in contact and can be either static or kinetic.
Huygens: Huygens is a principle in wave theory that describes how each point on a wavefront can be considered a source of secondary wavelets, which spread out in the forward direction at the same velocity as the original wave. This principle is fundamental to understanding the behavior of waves, including their propagation, interference, and diffraction.
Inertia: Inertia is the resistance of an object to any change in its state of motion. It is directly proportional to the mass of the object.
Inertia: Inertia is the tendency of an object to resist changes in its state of motion. It is a fundamental property of matter that describes an object's resistance to changes in its velocity or direction of motion.
Linear Velocity: Linear velocity is the rate of change of an object's position along a straight line. It is a vector quantity, meaning it has both magnitude and direction, and is typically measured in units of distance per unit of time, such as meters per second (m/s).
Meters/second²: Meters per second squared (m/s²) is a unit of acceleration, which measures the rate of change in velocity over time. It represents the amount of change in velocity (in meters per second) that occurs in one second. This unit is particularly relevant in the context of centripetal acceleration, which describes the acceleration experienced by an object moving in a circular path.
Newton: The newton (N) is the standard unit of force in the International System of Units (SI). It is named after the famous English physicist Sir Isaac Newton, who made significant contributions to the understanding of the concept of force and its role in the laws of motion.
Newton's Second Law: Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting upon it and inversely proportional to its mass. This law describes the relationship between an object's motion and the forces acting upon it, providing a fundamental principle for understanding the dynamics of physical systems.
Normal force: The normal force is the perpendicular contact force exerted by a surface on an object resting on it. It counteracts the weight of the object.
Normal Force: The normal force is a contact force that acts perpendicular to the surface of an object in response to an external force pressing the object against the surface. It is a fundamental concept in classical mechanics, particularly in the study of Newton's laws of motion.
Radians/second: Radians per second is a unit of angular velocity that measures the angle in radians that an object rotates through in one second. This unit is crucial for understanding rotational motion, as it provides a way to quantify how quickly an object is spinning or moving in a circular path. It connects directly to concepts like centripetal acceleration, which describes the acceleration experienced by an object moving in a circular path, as this acceleration is dependent on the angular velocity of the object.
Radius: The radius is the distance from the center of a circle or sphere to its circumference or surface. It is a fundamental geometric property that defines the size and shape of circular and spherical objects.
Tangential Motion: Tangential motion refers to the motion of an object along the tangent line of a curved path. It is the component of an object's motion that is perpendicular to the radial or centripetal direction, and it is a crucial concept in understanding the dynamics of circular motion and centripetal acceleration.
Tangential Velocity: Tangential velocity is the rate of change of an object's position along the tangent to its circular path. It represents the velocity of an object moving in a circular motion, perpendicular to the radius of the circle.
Tension: Tension is the force transmitted through a string, rope, cable, or similar object when it is pulled tight by forces acting from opposite ends. This concept is crucial in understanding how forces interact in various systems, as it provides insights into how objects transmit forces and maintain equilibrium.
Ultracentrifuge: An ultracentrifuge is a high-speed centrifuge used to separate particles in a solution based on their size, shape, and density. It operates at extremely high speeds to generate significant centripetal acceleration.
Uniform Circular Motion: Uniform circular motion is the motion of an object traveling in a circular path at a constant speed. While the speed remains constant, the direction of the object's velocity continuously changes, leading to a consistent acceleration toward the center of the circle, called centripetal acceleration. This type of motion involves forces acting inwards, known as centripetal forces, and can be analyzed using concepts like angular acceleration and connections to oscillatory behavior.
V²/r: The term v²/r represents the centripetal acceleration experienced by an object moving in a circular path. It is the formula that describes the acceleration directed toward the center of the circular motion, which is responsible for maintaining the object's curved trajectory.
ω²r: ω²r is a mathematical expression that represents the centripetal acceleration experienced by an object moving in circular motion. It is the product of the square of the angular velocity (ω) and the radius (r) of the circular path. This term is crucial in understanding the dynamics of circular motion and the forces acting on an object as it travels along a curved trajectory.
© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.
Glossary
Glossary