Understanding Position – Time Graphs

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Mr. Hand’s Science Site

 

Horizontal Line = Stopped!

Look at the red line, which shows the position of an object over time. Is the object moving? No.

 

 

Positive and Negative Motion

Up is +. Pink is +. Down is negative. Green is negative.

 

Steeper lines are faster. The Green line is faster than the pink line.

 

In fact, the speed of the green line is -60/6 or -10 cm/s while the speed of the pink line is roughly 30/10 or 3 cm/s. It doesn’t matter that green is negative.

 

Click here to learn how to calculate average speed.

 

 

 

 

Horizontal Line = Stopped!

Curving lines = Acceleration!

Curving lines = Acceleration!

 

Object is slowing down

Net force is causing an acceleration

 

Object is speeding up

Net force is causing an acceleration

 

Constant Speed

No Net Force.

Acceleration = Zero

Moving in negative direction and then slowing down.

Net force is causing an acceleration

 

Velocity of a Line

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