Key Terms

acceleration vector

instantaneous acceleration found by taking the derivative of the velocity function with respect to time in unit vector notation

angular frequency

$\omega ,$ rate of change of an angle with which an object that is moving on a circular path

centripetal acceleration

component of acceleration of an object moving in a circle that is directed radially inward toward the center of the circle

displacement vector

vector from the initial position to a final position on a trajectory of a particle

position vector

vector from the origin of a chosen coordinate system to the position of a particle in two- or three-dimensional space

projectile motion

motion of an object subject only to the acceleration of gravity

range

maximum horizontal distance a projectile travels

reference frame

coordinate system in which the position, velocity, and acceleration of an object at rest or moving is measured

relative velocity

velocity of an object as observed from a particular reference frame, or the velocity of one reference frame with respect to another reference frame

tangential acceleration

magnitude of which is the time rate of change of speed. Its direction is tangent to the circle.

time of flight

elapsed time a projectile is in the air

total acceleration

vector sum of centripetal and tangential accelerations

trajectory

path of a projectile through the air

velocity vector

vector that gives the instantaneous speed and direction of a particle; tangent to the trajectory