motion review. what is the difference between an independent and dependent variable?

MotionReview

What is the difference between an independent and dependent variable?

Which is the D.V. and I.V.?

Look at the following images below, what are the observables and measureables?

What are your Observables?

Possibilities:

Size

Color

Texture

What are your Measureables?

Possibilities:

Circumference

Area

Radius

Diameter

Write a Possible Question and Identify the Dependent & Independent Variables

Independent Variable:

Ex: Area

Dependent Variable:

Ex: Circumference

Question:

Ex: How does circumference of a circle depend on area?

Linearizing Data

Does the graph shown below need to be linearized? Why or why not?

How would you linearize this data? To linearize:

Y = 1/X

Or

P = 1/V

What is the difference between distance,

displacement, and position?

What is the difference between velocity and speed?

What are the equations and units for:Speed

and Average Velocity?

Speed = Distance/ Time

Average Velocity= ∆x/∆t = change in displacement/ change in

time

Units: m/s

Calculate This Speed

A football field is about 100 m long. If it takes a person 20 seconds to run its length, how fast was the football player running?

Calculate this Speed:

A football field is about 100 m long. If it takes a person 20 seconds to run its length, how fast was the football player running?

Speed = Distance ÷ Time

Speed = 100 m ÷ 20 sSpeed = 5m/s

Remember to include

the UNITS!!

What is the difference between average and instantaneous

velocity?

Average velocity is the overall change in displacement over time. Instantaneous velocity tells you how fast an object is going at a specific time. Instantaneous velocity is the slope of the tangent line on a position vs. time graph.

Interpret The Graph Below:

Pos

ition

Interpret The Graph Below:

The graph shows an object which is not moving (at rest).

The distance stays the same as time goes by because it is not moving.

Pos

ition

Interpret The Graph Below:

Pos

ition

Interpret The Graph Below:

The graph showsthat the objects distance increases as time passes.The object is moving and so it has velocity.

The straight line shows it is a constant (not changing).

Pos

ition

Interpret The Graph Below:

Pos

ition

Interpret The Graph Below:

Just like the previous graph, this graph shows an object moving with constant velocity

Pos

ition

Interpret The Graph Below:

Pos

ition

Interpret The Graph Below:

In the first part of the graph the object is moving with constant velocity.

In the second part of the graph the object is at rest (not moving).

In the third part the object is again moving with constant velocity.

Pos

ition

What is Acceleration?

Describe Acceleration

• A change in velocity – which may be:– A change in speed

• Starting• Stopping• Speeding up• Slowing down

– A change in direction

More

Describing AccelerationNegative Acceleration describes an object

with a negative change in velocity over time. This could mean that the object is slowing down or that it is traveling in a negative direction.

Positive Acceleration describes an object that has a positive change in velocity over time. This could mean that an object is speeding up.

Interpret The Graph Below:

Pos

ition

Interpret The Graph Below:

The curve in the graph shows that the objects velocity is changing as time passes.

This is acceleration.

Pos

ition

Interpret The Graph Below:

Interpret The Graph Below:

The graph showsthat the objects velocity does not change as time passes.

It shows constant velocity.

Interpret The Graph Below:

Interpret The Graph Below:

The graph showsthat the objects velocity is increasing as time passes – it is accelerating.

The straight line shows that it is constant acceleration.

What would the acceleration vs. time graph look like?

Acc

eler

atio

n (m

/s2)

Relationships

The slope of a position vs. Time graph:

Velocity

The slope of a velocity vs. Time graph:

Acceleration

The area under a velocity vs. time graph:

Change in Displacement