Kinematics

(Stuff moving)

(stuff)

Start with vocabulary

• Position – where it is• Displacement – how far it moved, direction

(+/-) is important• Velocity – how fast it moves, direction is

important (+/-)– Instantaneous, right now! Slope of tangent

• Average velocity – change in position divided by change in time

Vocabulary, continued

• Acceleration – rate of change in velocity– Instantaneous, Slope of velocity time curve– Average, over time interval– Our equations apply only to contsant

acceleration– When acceleration changes, we break the

problem into chunks of constant acceleration

The Equations!

200 2

1attvdd

dv

t

t

va

tvv

d f

2

)( 0

davv f 220

2

0v v at

Daddy

dva

dt

200 2

1attvdd

0v v at

Definitions

dv

t

t

va

Mommy

davv f 220

2

Notice no time in this one!

One more!

0( )

2fv v

d t

v

t

0( )

2fv v

d t

Avg velocity

The Equations!

200 2

1attvdd

dv

t

t

va

tvv

d f

2

)( 0

davv f 220

2

0v v at

Decipher word problems

• …at rest, …from rest – not moving at beginning… v0 = zero!

• …Travels 10 m in 10 sec…– df=10m, t=10 s

• …reaches a maximum height– velocity at hmax = zero!

Kinematics Examples

Freefall Examples

• Same kinematics equations…

• Just constant acceleration of

g=9.8 m/s2

• toward mother earth.

Freefall Cases

• Downy

• Uppy

• Uppy - downy

Wrap up

• Givens

• Unknowns

• P&P

• E– Time or none given

• S & S & S

On site problem work

• More example problems from the worksheets

The Equations!

200 2

1attvdd

dv

t

t

va

tvv

d f

2

)( 0

davv f 220

2

0v v at