Motion

Describing Motion

Objects in motion may not be as they appear,

or are they??

Motion is defined as the change of position over time.

A change in position is evidence that motion
has happened.

MOTION

Open Ended

What type of force causes an object to be in motion?

Open Ended

What is a change in position?

Reference Points

A reference point is a place or object used for

comparison to determine if something is in
motion.

An object is in motion if it changes position

relative to a reference point.

Objects that we call stationary—such as a

tree, a sign, or a building—make good
reference points.

Multiple Choice

What type of objects make good reference points?

• Moving objects

• Stationary objects

• Big objects

• Small objects

Open Ended

Give me another example of a stationary reference point.

Choosing a Reference Point to

Determine Location

1. You may choose a specific stationary location.

For example, you might say;
Freehold Borough is 20 miles West of Ocean Township.

Amy’s house is 1 block south of John’s house.

Jane is sitting 10 feet North of the big Oak tree in the field.

2. You may use the Longitude and Latitude System, where
location is described by how many degrees north or south it is
from the equator and how many degrees east or west it is from
the prime meridian. The reference point is 0 degrees longitude
and 0 degrees latitude.

All global locations can be determined using this
system.

OR……

Moving Reference Point

⚫ You probably know what happens if your reference

point is moving.

Have you ever been in a car and feel like you are

moving backwards, but, then you realize that it
is the other car that is moving???

Your car seemed to move backwards because you

were using the other car as a reference point.

Figure 1Reference Points The passenger can use a tree as a reference point
to decide if the train is moving. A tree makes a good reference point because it
is stationary from the passenger’s point of view.

Multiple Choice

If Kyle walks 3 blocks south from his home to school, and Jen walks 2 blocks north from her home to Kyle’s home, then how far, and in what direction is the school from Jen’s home?

• 1 block South

• 5 blocks South

• 1 block North

• 5 blocks North

Open Ended

What is the difference between distance and displacement?

Multiple Choice

If a soccer player runs after his opponent 50 m North, then turns around and chases him 20 m South, what is his distance?

• 70 m

• 30 m

• You can't find out the distance with the information.

• He needs to run faster

Multiple Choice

Mali loves to make herself dizzy. She spins around in place 7 times before falling down right where she was standing. What is her displacement?

• 0

• 10

• -10

• -0

Multiple Choice

Little Jimmy ran from point A to point B, then to Point C, and finally to Point D. What is little Jimmy's displacement?

• 0 m

• 5 m

• 11 m

• 16 m

Speed = Distance

Time

SPEED

Instantaneous Speed = speed at that
very moment in time

Average speed = How far you have traveled in
a given amount of time.