Interpreting Motion Graphs

Motion• A change in position measured by

distance and time.

Speed• The rate at which an object moves.

Velocity

• The speed and direction of a moving object.

Acceleration

• The rate, speed, or direction changes.

Reference Point• A place or object used for comparison to

determine if something is in motion.

So…a fly is sitting on the shoulder of a man sitting in a car. The car is traveling at 60 mph. Is the fly in motion?

Key Points

• A straight line shows constant speed.

• A curved line shows average speed.

• A horizontal line shows no motion.

• Time is on the x-axis, distance (OR SPEED) is on the y-axis.

• The steeper the graph, the faster the motion.

Distance-Time Graphs

• Time is always on the x-axis. Distance is always on the y-axis.

Speed-Time Graphs

• Time is always on the x-axis.

Speed is always on the y-axis.

Spe

ed

Distance-Time: NO MOTION

• Time is increasing, but distance does

NOT change. It is NOT MOVING…

NO MOTION…AT REST.

Speed-Time: CONSTANT SPEED

• Time is increasing, but

speed does NOT change. It is moving at a

constant speed.

Spe

ed

Distant-Time: CONSTANT SPEED• Time and distance are

INCREASING at a constant rate. This

graph shows CONSTANT

SPEED.

Speed-Time: CONSTANT SPEED• Time and

speed are INCREASING at

a constant rate. This

graph shows CONSTANT

SPEED.

Spe

ed

Distance-Time: CONSTANT SPEED• This graph shows a

change in direction (meaning the object

is headed back to the starting point).

This graph also shows CONSTANT

SPEED.

Speed-Time: CONSTANT SPEED• This graph shows time is INCREASING

while speed is DECREASING at a

constant rate. This graph also shows

CONSTANT SPEED.

Speed

Distance-Time: FASTER SPEED

• A steeper line shows greater

distance traveled in a given time.

The STEEPER THE LINE, the HIGHER THE

SPEED.

Speed-Time: FASTER SPEED• A steeper line

shows speed increasing in

shorter amount of time. The

STEEPER THE LINE, the

HIGHER THE SPEED.

Spe

ed

Distance-Time: ACCELERATION• In a given time,

the distance the object

moves is getting larger, it is

ACCELERATING. The curve

upward shows an INCREASE in

SPEED.

Speed-Time: ACCELERATION• In a given time,

the speed at which the object is

travelling is increasing, it is ACCELERATING.

The curve upward shows an INCREASE in

SPEED.

Spe

ed

Initially, the object is

traveling at a slower speed

Then, the speed

increases rapidly

Distance-Time: DECELERATION• This graph is

the same as above, but the

curve downward

shows DECELERATION or a DECREASE

IN SPEED.

Speed-Time: DECELERATION• In a given time,

the speed at which the object

is travelling is decreasing, it is DECELERATING.

The curve downward shows

a DECREASE IN SPEED.

Spe

ed

The speed rapidly declines and the object

slows down

Initially, the object is traveling at a very fast

speed.

Putting it all together

Putting it all togetherS

peed constant

speed

decreasing speed at a constant

rate

increasing speed at a

constant rate