Chapter 3 Vocab.
Resultant – The new vector formed when adding two vectors together.
Component - One of the vectors (usually two vectors and they are usually perpendicular to each other) whose sum is a resultant vector. Any resultant vector may be regarded at the combination of two or more component vectors.
Resolution (resolve) - The breaking down of a magnitude and direction (vector) into its x and y components using trigonometry.
Projectile - Any object that moves through the air (or space), acted on only by gravity (and possibly air resistance). A projectile is any body that is given an initial velocity and then follows a path determined by the effect of the gravitational acceleration.
Linear motion – Motion in a straight line, either horizontal (x or y axis) or vertical (z-axis).
Two-Dimensional Motion - Motion that lies in a plane but not necessarily in a straight-line path. For example an object projected off a table moves both horizontally (x or y axis) and vertically (z-axis).
Distance - The absolute value of length from something or amount of length traveled by a moving object. Example: 5 steps forward and 3 steps backward is 8 steps of total distance.
Displacement - The change in position of something. How far you are from where you started. Example: 5 steps forward and 3 steps backward the displacement is 2 steps forward.
Velocity - speed in a given direction
Instantaneous Velocity (Speed) – how fast you are going at a given instant in time
Acceleration - the rate of change of velocity with respect to time. Mathematically expressed as
Free Fall - describes an object that is accelerating under only the force of gravity
Air resistance - friction between a moving object and the surrounding atmosphere. Air resistance always acts in the direction opposite to which the object is moving
Hang time - The total time a rising and falling object spends in the air.
Apex - (zenith, peak, summit etc.) The highest point a rising and falling object attains during its (hang) time in the air.
Vertex - The point of zero velocity in the y direction associated with highest point a rising and falling object attains during its (hang) time in the air.
Range - The maximum horizontal distance a projectile can travel.
Magnitude – a numerical value that describes the amount (size) of something. For example moving 4 m North and 3 m East gives you a distance magnitude of 5 m.
Vector - A quantity that expresses both a magnitude (amount) and a direction. For example moving 4 m North and 3 m East gives you a displacement of 5 m 37 E of N.
Scalar - A quantity that completely described by magnitude (size) only. For example moving 4 m North and 3 m East gives you a distance magnitude of 5 m.
Head wind – wind moving in the opposite direction as the object is moving. For example if you are moving due North a head wind would be blowing due South.
Tail wind – wind moving in the same direction as the object is moving. For example if you are moving due North a tail wind would be blowing due North.