L3: Understanding Distance-Time Graphs (7.7C)

What does a horizontal line on a distance-time graph indicate about the object's motion?

• The object is moving at a constant speed.

• The object is not moving.

• The object is accelerating.

• The object is decelerating.

Answer explanation

A horizontal line on a distance-time graph indicates that the distance remains constant over time, meaning the object is not moving.

How can you differentiate between a graph showing constant speed and one showing changing speed on a distance-time graph?

• Constant speed is shown by a curved line, while changing speed is shown by a straight line.

• Constant speed is shown by a straight line, while changing speed is shown by a curved line.

• Both constant and changing speeds are shown by straight lines.

• Both constant and changing speeds are shown by curved lines.

Answer explanation

A distance-time graph shows constant speed as a straight line, indicating equal distance covered over equal time intervals. In contrast, changing speed is represented by a curved line, reflecting varying distances over time.

Tags

NGSS.MS-PS3-1

If a distance-time graph shows a line that slopes upwards, what does this indicate about the object's motion?

• The object is moving backward.

• The object is moving forward.

• The object is stationary.

• The object is moving in a circular path.

Answer explanation

An upward slope on a distance-time graph indicates that the distance is increasing over time, meaning the object is moving forward.

On a distance-time graph, how would you calculate the average speed of an object?

• By finding the area under the graph.

• By dividing the total distance by the total time.

• By multiplying the total distance by the total time.

• By subtracting the initial distance from the final distance.

Answer explanation

To calculate average speed on a distance-time graph, divide the total distance traveled by the total time taken. This gives the average speed, which is a key concept in understanding motion.

What does a steeper slope on a distance-time graph indicate about the object's speed?

• The object is moving slower.

• The object is moving faster.

• The object is not moving.

• The object is moving at a constant speed.

Answer explanation

A steeper slope on a distance-time graph indicates that the object covers more distance in the same amount of time, meaning it is moving faster.

Tags

NGSS.MS-PS3-1

If a distance-time graph shows a line that curves upwards, what does this indicate about the object's motion?

• The object is moving at a constant speed.

• The object is accelerating.

• The object is decelerating.

• The object is stationary.

Answer explanation

A distance-time graph that curves upwards indicates that the distance is increasing at an increasing rate, which means the object is accelerating.

Tags

NGSS.MS-PS3-1

Which of the following best describes the motion of an object if its distance-time graph is a straight line with a negative slope?

• The object is moving forward at a constant speed.

• The object is moving backward at a constant speed.

• The object is accelerating forward.

• The object is decelerating backward.

Answer explanation

A straight line with a negative slope on a distance-time graph indicates that the object is moving backward. Since the slope is constant, the object is moving backward at a constant speed.

Tags

NGSS.MS-PS3-1

How can you determine the speed of an object at a specific point on a distance-time graph?

• By finding the slope of the tangent line at that point.

• By finding the area under the graph at that point.

• By finding the y-intercept of the graph.

• By finding the x-intercept of the graph.

Answer explanation

The speed of an object at a specific point on a distance-time graph is determined by the slope of the tangent line at that point. The slope represents the rate of change of distance with respect to time.

Tags

NGSS.MS-PS3-1

If a distance-time graph shows a line that curves downwards, what does this indicate about the object's motion?

• The object is accelerating.

• The object is decelerating.

• The object is moving at a constant speed.

• The object is stationary.

Answer explanation

A distance-time graph that curves downwards indicates that the distance covered by the object is decreasing over time, which means the object is slowing down. Therefore, the object is decelerating.

Tags

NGSS.MS-PS3-1

An object travels 150 meters in 30 seconds. What is its average speed?

• 3 m/s

• 5 m/s

• 10 m/s

• 15 m/s

Answer explanation

To find average speed, divide distance by time. Here, average speed = 150 meters / 30 seconds = 5 m/s. Thus, the correct answer is 5 m/s.