Chapter 1- Representing Motion

Motion

The change in objects position or orientation with time.

• straight line motion

• circular motion (along circular path)

• projectile motion (object through air)

• rotational motion (spinning of object without axis)

Base units

• meters (length), kilogram (mass), seconds (time)

• building blocks for other units

• can form other units called derived units

Trajectory

The path along which an object moves; can be either straight or or curved

Position

location at a particular instant in time

Displacement

Change in position; can be either positive or negative

• Delta X

• Delta X = X2 - X1 (final-initial position)

Origin

Fixed reference point on where all distances are measure from

Coordinate system

Describes positions of objects along an axis

• location on coordinate system is called position

Uniform Motion

Velocity is constant; motion at a constant

• distance between frames is constant

• can be either negative or positive

Velocity

V= deltaX/delta T

• tells us about both and objects speed and direction

• can be negative or positive

Speed

always a positive number and doesn’t care about direction

• distance traveled/ time it took

Velocity vector

Graphically taking arrows to find Delta X

• velocity and displacement

• longer velocity vectors mean increase in speed

Scalar quantities

Has just magnitude or size

• Temperature, time, speed , and mass

Trig

• Sin θ = opposite side/hypotenuse

• Cos θ= adjacent side/ hypotenuse

• tanθ = opposite side/adjacent

• θ= Cos^-1(a/c)

• θ = Sin ^-1(b/c)

• θ= tan^-1(b/a)

• C= square root of a² + b²