Physics Concepts: Kinematics and Dynamics Definitions

Physics Concepts: Kinematics and Dynamics

ETAPA 2: Gravity and Projectile Motion

• Free Fall: The movement described by a body when it moves freely under the influence of gravity.
• Horizontal Projectile Motion: The motion a body describes when thrown from a certain height in a horizontal direction; its trajectory is the combination of a horizontal and a vertical motion.
• Aristotle: He asserted that bodies fall with a velocity proportional to their weight, and the falling time was inversely proportional to it.
• Parabolic Projectile Motion: The most common projectile motion, consisting of throwing an object in a direction that forms an angle with the horizontal at a certain velocity.
• Gravitational Acceleration: The natural magnitude all bodies possess when they fall or are thrown upwards to later return to Earth.
• Galileo Galilei: He asserted that if two bodies are dropped from the same height, both will fall at the same time since weight is independent of velocity.
• Vertical Projectile Motion: The motion a body describes when it is thrown up or down and then moves under the action of gravity.
• Movement in Two Dimensions: It establishes that any movement in nature can be analyzed as the combination of two or more autonomous rectilinear movements.

ETAPA 1: Motion and Forces Fundamentals

Kinematic Variables

• Kinetic: The variable that represents the area under the graph of velocity versus time (v vs t).
• Acceleration: The variable that represents the slope of the graph of velocity versus time (v vs t).
• Velocity: The variable that represents the slope of the graph of position versus time (x vs t).

Types of Motion

• The Uniform Rectilinear Motion is the motion in which the body moves in a straight line at constant velocity and speed.
• The Uniformly Accelerated Rectilinear Motion is the motion in which a body moves in a straight line with constant acceleration.
• The Rectilinear Motion is the motion a body has when its trajectory is a straight line.

Conditions of Motion

• When the velocity is constant, the acceleration is zero.
• When the body starts from rest, the initial velocity is zero.

Equilibrium Concepts

• Equilibrium: The condition that occurs when the resultant force acting on a body is equal to zero.
• Static Equilibrium: The type of equilibrium which occurs when the body remains at rest.
• Dynamic Equilibrium: The type of equilibrium which occurs when the body moves at a constant velocity.

Newton's Laws of Motion

• The 1st Law of Newton states that: “An object will remain at rest or in uniform rectilinear motion unless acted upon by an external force.”
• The 2nd Law of Newton states that: “When a body is under the action of an unbalanced net force, the acceleration produced is directly proportional to the force and inversely proportional to the mass of the body.”
• The 3rd Law of Newton states that: “For every action force there is an equal and opposite force called reaction.”