1d kinematics - displacement, velocity, acceleration

kinematics

the description of how objects move

displacement of an object

change in position of the object, vector

displacement/distance

description of the motion of any object must always be given relative to a reference point or origin point from which positions are measured (straight line and direction)

vector

has magnitude and direction (ex: velocity, displacement, momentum, torque)

distance

total length of path travelled by an object (height, how far), scalar

displacement unit

metres

distance unit

metres

scalar

has no direction or sign, only magnitude (reference points don’t matter) ex: speed, distance, time, heat, energy, work

time units

seconds

average velocity of an object

displacement of an object per unit time, vector

velocity units

meters per second

speed of an object

the distance an object travels per unit time, scalar version of velocity

average acceleration of an object

the change of velocity of the object per unit time, vector, not always same direction as velocity

acceleration units

metres per second²

gravity

negative acceleration (down)

velocity and acceleration relationship

same direction means speeding up in whatever direction, opposite means slowing down

decaleration

slowing down, not equal to negative acceleration

coordinate system

up and right are positive

velocity and acceleration

independent variables - velocity is a vector, so acceleration can be a change in the magnitude of velocity or a change in the direction of velocity