AP PHYSICS Notes -

Kinematics

Definition of Mechanics: The study of motion of objects

Definition of Kinematics: is a branch of mechanics that describes the motion of objects using words, diagrams, numbers, graphs and equations.

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Scalars are quantities that are fully described by a magnitude (or numerical value) alone.

Vectors are quantities that are fully described by both a magnitude and a direction.

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Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion.

Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

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Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance.

Velocity is a vector quantity that refers to "the rate at which an object changes its position." The direction of the velocity vector is simply the same as the direction that an object is moving. It would not matter whether the object is speeding up or slowing down.

—> Avg. Speed Equation: Distance traveled / time

—> Avg. Velocity Equation: Change in position / time

Acceleration is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity.

Sometimes an accelerating object will change its velocity by the same amount each second. This is referred to as a constant acceleration since the velocity is changing by a constant amount each second. j