Describing Motion

Scalars and Vectors A scalar quantity is one that can be completely explained by using just its magnitude (number) and units Ex: speed, distance, volume, mass, time Ex: This classroom has a scalar magnitude of 12 meters. Ex: I drive my car at 45 mph on my way to work

A vector quantity must have both its magnitude (number) and its direction (left/right/up/down/NSEW) Ex: velocity, acceleration, forces Ex: To be more specific, I might say I drive my car 45 mph to the east Ex: I pushed my grocery cart with a magnitude of 50 Newtons to the right.

Distance vs. Displacement Distance and displacement are two quantities which may seem to mean the same thing, but they actually have different meanings in Physics Now we can put the ideas comparing scalar and vector quantities to work! Here’s our first physics concept…

Distance is a scalar quantity = the sum of all the objects movements formula is x final = x 1 + x 2 + x 3 … Displacement is a vector quantity = the objects overall change in position formula is Δx = x f - x i Note: a Δ (Greek letter delta) means “change in”

Using the number line below, calculate the following four displacements in your notes: formula is Δx = x f – x i a.If x i = 5 and x f = 10 b.If x i = 5 and x f = 1 c.If x i = -5 and x f = 2 d.If x i = -5 and x f = -10

Calculate the distance and displacement if you walked one lap around this rectangle. Distance = Displacement =

Calculate the distance and displacement traveled by the skier in these three minutes. Distance = Displacement =

A football coach paces back and forth along the sidelines for 10 minutes. What is the coach’s resulting displacement and distance traveled at the end of the 10 minutes? Distance = Displacement =

Conversions and Other Important Info sin = o/h cos = a/h tan = o/a

Conversions and Other Important Info Pythagorean Theorem Common Metric Quantities Millimeter 1/1,000 th of a meter Centimeter 1/100 th of a meter Meter 1 Kilometer 1,000 meters Hour 1 Minutes 60 minutes Seconds 3,600 seconds