1 D Motion Time and How Far Time

1 D Motion Time and How Far

Time • You can talk about an instant in time or an interval of time

Time • “What time does class end? ” An instant of time. • ti = initial instant of time tf = final instant of time

Time • “How long does class last? ” • time interval • ∆t = tf – ti (final time – initial time) Note: Greek letter delta (∆) = change

Time in a motion graph • Time is ALWAYS the independent variable on the x-axis on a motion graph

How far? 3 different answers 1. distance – the length of the trip you traveled 2. position – where you are from a reference point 3. displacement – the overall change in position– path does not matter change in position (xf – xi or ∆x)

How far? 3 different answers Start at position -2 and move right 5 units and then left 4 units 1) distance – the length of the trip you traveled

How far? 3 different answers 2) position – where you are from a reference point (distance & direction) The position axis along which an object moves:

How far? 3 different answers 3) displacement – from start to stop of a trip (distance and direction) The position axis along which an object moves:

SCALAR Magnitude Time VECTOR Magnitude & direction

SCALAR Magnitude Time Distance VECTOR Magnitude & direction Position Displacement

Walk it • Mailbox = reference point • position, distance, displacement