Motion Graphs

Distance vs. Time

Graphs

Motion Graphs

• Show the motion of an object in a graph.

• Graphs can help make motion easier to picture and understand

Distance-Time Graphs

• Time is always on the X-axis (bottom of the graph)

• Distance is always on the Y-axis (side of the graph)

Objects Not Moving/At Rest

• When an object is NOT moving, a horizontal line is shown on a distance-time graph

• Time is increasing to the right but the distance does not change.

Objects moving at a Constant Speed

• Time is increasing to the right and distance is increasing constantly with time.

• Constant speed is shown by straight lines on a graph.

Two objects moving at a constant speed

• The steeper line shows an object moving at a greater speed.

• It is covering a greater distance in a shorter period of time.

• Both lines are straight so both speeds are constant.

An Object Accelerating

• A curved line shows an object that is accelerating

• In this case the object shows in increase in speed since the line is getting steeper.

What is the motion of the object in the graph below?

• No motion • Moving away fast at a constant speed• Stopped (no motion)• Moving away more slowly at a constant speed• Stopped (no motion)

What is the motion of the object in the graph below?

• Moving away at a constant speed• Stopped moving (no motion)• Accelerating

Distance Time Graphs Review

Practice Reading a Graph

• What is the motion of the object in the graph?

– Constant Speed

– The line is straight so the object is moving at a constant speed.

What is the Speed of the object? Speed = distance ÷ time

• 5 meters in 1 sec.• 25 meters in 5 sec.• 50 meters in 10 sec.

• 5 ÷ 1 = 5 m/s• 25 ÷ 5 = 5 m/s• 50 ÷ 10 = 5 m/s

This object is travelling at a constant speed of 5 m/s (meters per second)

Interpret the graph below

• Which car is traveling the fastest?– Car D

• Which car is traveling the slowest?– Car A

• Which car is traveling at a speed of 30 Km/h?– Car C