Question

introduction to position - time graphs
position - time graphs tell you where an object is located over a period of time. the slope of the graph tells you how fast the object is moving.
the sign of the slope indicates direction of motion. what would a graph look like if an object is...
moving away from 0 meters
stopped
moving towards 0 meters
the steepness of the line indicates how fast an object is moving. what would a graph look like if an object is...
moving slowly away from 0 m.
moving quickly away from 0 m.
moving slowly towards 0 m.
if an object’s motion changes, the slope of the line changes. what would a graph look like if an object is...
moves slowly then quickly away from 0 m.
moves quickly towards 0 m, then stops.
is not moving, the moves slowly towards 0 m.
practice: answer the following questions using the graphs
position - time graph

1. when time increases, what happens to the distance?
2. describe the object’s motion.
3. what is the velocity of the object?

position - time graph

1. when time increases, what happens to the distance?
2. describe the object’s motion.
3. what is the velocity of the object?

Explanation:

Step1: Analyze first graph

For the first position - time graph with a positive - sloped straight line.

Step2: Answer question 1

As time increases, the distance increases because the line has a positive slope.

Step3: Answer question 2

The object is moving at a constant speed away from the starting point (0 meters) since it has a straight - line positive - sloped graph.

Step4: Calculate velocity for question 3

The velocity \(v=\frac{\Delta x}{\Delta t}\). If we take two points, say \((0,0)\) and \((10, 20)\), then \(v=\frac{20 - 0}{10 - 0}=2\) m/s.

Step5: Analyze second graph

For the second position - time graph with a negative - sloped straight line.

Step6: Answer question 4

As time increases, the distance decreases because the line has a negative slope.

Step7: Answer question 5

The object is moving at a constant speed towards the starting point (0 meters) since it has a straight - line negative - sloped graph.

Step8: Calculate velocity for question 6

If we take two points, say \((0,20)\) and \((10,0)\), then \(v=\frac{0 - 20}{10 - 0}=- 2\) m/s.

Answer:

1. The distance increases.
2. The object is moving at a constant speed away from 0 meters.
3. 2 m/s
4. The distance decreases.
5. The object is moving at a constant speed towards 0 meters.
6. - 2 m/s