Defintion of DTG

Question

"On a distance-time graph, the slope of a line segment could be a positive number, zero or a negative number. Explain what each of these means."

 

Could I get help on what these(s) mean?

Answer 1

Amber,

 

If distance is the y-axis and time is the x-axis on the graph, then a line with a positive slope would be oriented from the lower left to the upper right.  That means distance increases as time increases.

 

If the slope is negative, then the line is oriented from the top left to lower right and means distance decreases as time increases.

 

If the slope is zero, then the line is parallel to the x-axis and means that the distance doesn't change as time increases.

 

Try to draw these; it will make things clearer.

Answer 2

On a Distance-Time Graph, the slope represents how distance changes with time; that is, it represents the velocity of the object.  For straight line slopes, the velocity is constant:

1. If the slope is increasing (positive) then the distance increases as time increases.  This means that the object is moving away from you at a constant speed
2. If the slope is decreasing (negative), the distance gets smaller as time increases.  This means that the object is moving toward you at a constant speed
3. If the slope is zero, then the distance stays the same as time increases.  This means that the object is not moving