Essential Knowledge 3.A.1 💁♀️
An observer in a reference frame can describe the motion of an object using such quantities as position, displacement, distance, velocity, speed, and acceleration.
Key Concept: Frame of Reference
A coordinate system in relation to which judgments can be made, usually from an observer’s point of view, is known as a frame of reference. A frame of reference moving with constant velocity is known as an inertial frame of reference. 🙋♀️🙋♂️
Rotational Velocity and Acceleration:
Image courtesy of Giphy.
Essential Knowledge 3.A.2 💥
Forces are described by vectors.
Key Vocabulary: Vector
Quantities that are described by a size (magnitude) and a direction (ex. East, Up, Right, etc.)
Example: The gas station is five miles west from the car
A force can be simply described as a push or pull. We know that a push or pull has both magnitude and direction (therefore, it is a vector quantity) and can vary considerably in both regards.
Essential Knowledge 3.A.3 🔊
A force exerted on an object is always due to the interaction of that object with another object.
Force is always the result of an interaction of two or more objects. No object has force on its own. Therefore, no object can exert a force on itself. When you clap your hands, one hand exerts a force on the other. When you throw a ball, it exerts a force on your hand and your hand exerts a force on it.
Essential Knowledge 3.A.4 ↔️
If one object exerts a force on a second object, the second object always exerts a force of equal magnitude on the first object in the opposite direction.
Newton’s Third Law States, “For every action, there is an equal and opposite reaction.” Simply put, in every interaction, there is a pair of forces acting on the two interacting objects. The magnitude of the force on the first object equals the magnitude of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs.
🎥Watch: AP Physics 1 - Unit 3 Streams