Physical Science-Chapter 11

# Kinematics

# 11A Describing Position

Wandering Planets

Mechanics: the study of motion

Kinematics: the study of how things move

Dynamics: the branch of physics that studies forces and how they can change an object’s motion

History of Mechanics

Retrograde Motion: the apparent motion of some planets in which they appear to slow down, stop, reverse their direction, and then resume their normal motion

Quantum Mechanics: the branch of physics that explores the behavior of matter and energy at the atomic and subatomic level

Relativistic Mechanics: the study of the motion of objects whose speeds are near the speed of light

Frame of Reference

Frame of reference: a coordinate system used to describe the motion of an object

Distance and Displacement

Distance: how far an object moves during a time interval

Displacement: a vector quantity that describes a change in position

Scalars and Vectors

Scalar: a measurable quantity that consists of magnitude (size) only

Vector: a measurable quantity with both magnitude and direction

# 11B Describing Motion

Speed: a scalar quantity indicating the rate at which an object moves

Velocity: a vector quantity indicating the rate at which an object’s position changes

Momentum

Momentum: a property of a moving system that is equal to its velocity times its mass

Conservation of Momentum: states that within a closed system - a system that is isolated from outside. pushes or pulls - the total momentum remains constant

# 11C Changing Motion

Acceleration: the rate of change in velocity

Free Fall: the motion of an object that falls due to gravity alone, with no other forces acting on it

Two-Dimensional Motion

Circular Motion: movement along a circular path

Centripetal Acceleration: acceleration that causes an object to move along along a circular path

Projectile Motion: the two-dimensional motion of any flying object whose path is determined by the influence of an external force only, such as gravity

Trajectory: the curved path of a projectile

# Physical Science-Chapter 11

# Kinematics

# 11A Describing Position

Wandering Planets

Mechanics: the study of motion

Kinematics: the study of how things move

Dynamics: the branch of physics that studies forces and how they can change an object’s motion

History of Mechanics

Retrograde Motion: the apparent motion of some planets in which they appear to slow down, stop, reverse their direction, and then resume their normal motion

Quantum Mechanics: the branch of physics that explores the behavior of matter and energy at the atomic and subatomic level

Relativistic Mechanics: the study of the motion of objects whose speeds are near the speed of light

Frame of Reference

Frame of reference: a coordinate system used to describe the motion of an object

Distance and Displacement

Distance: how far an object moves during a time interval

Displacement: a vector quantity that describes a change in position

Scalars and Vectors

Scalar: a measurable quantity that consists of magnitude (size) only

Vector: a measurable quantity with both magnitude and direction

# 11B Describing Motion

Speed: a scalar quantity indicating the rate at which an object moves

Velocity: a vector quantity indicating the rate at which an object’s position changes

Momentum

Momentum: a property of a moving system that is equal to its velocity times its mass

Conservation of Momentum: states that within a closed system - a system that is isolated from outside. pushes or pulls - the total momentum remains constant

# 11C Changing Motion

Acceleration: the rate of change in velocity

Free Fall: the motion of an object that falls due to gravity alone, with no other forces acting on it

Two-Dimensional Motion

Circular Motion: movement along a circular path

Centripetal Acceleration: acceleration that causes an object to move along along a circular path

Projectile Motion: the two-dimensional motion of any flying object whose path is determined by the influence of an external force only, such as gravity

Trajectory: the curved path of a projectile