A car travels at a constant speed for 2 hours and covers a distance of 120 km. How would you represent this motion on a distance-time graph?

• A straight line with a positive slope

• A curved line with an increasing slope

• A horizontal line

• A straight line with a negative slope

Answer explanation

The car travels at a constant speed, covering 120 km in 2 hours. This results in a uniform increase in distance over time, represented by a straight line with a positive slope on a distance-time graph.

Tags

NGSS.MS-PS3-1

You are given a distance-time graph where the line is initially steep and then becomes less steep. 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 has stopped

Answer explanation

A steep line indicates a high speed, while a less steep line shows a decrease in speed. Therefore, the transition from steep to less steep means the object is decelerating.

A cyclist travels 30 km in 1 hour, then 20 km in the next hour, and finally 10 km in the last hour. How would you describe the cyclist's speed over time using a distance-time graph?

• The graph shows a straight line with a constant slope

• The graph shows a line with a decreasing slope

• The graph shows a line with an increasing slope

• The graph shows a horizontal line

Answer explanation

The cyclist's speed decreases over time: 30 km/h, then 20 km/h, and finally 10 km/h. This results in a line with a decreasing slope on the distance-time graph, reflecting the reduction in speed.

If a distance-time graph shows a horizontal line, what can you infer 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 horizontal line on a distance-time graph indicates that the distance does not change over time, meaning the object is not moving. Therefore, we can infer that the object is stationary.

An object moves with a constant speed of 5 m/s for 10 seconds. Calculate the total distance traveled and describe how this would appear on a distance-time graph.

• 50 meters; a straight line with a positive slope

• 50 meters; a curved line with an increasing slope

• 5 meters; a horizontal line

• 5 meters; a straight line with a negative slope

Answer explanation

The object travels at 5 m/s for 10 seconds, so the distance is 5 m/s * 10 s = 50 meters. On a distance-time graph, this is represented as a straight line with a positive slope, indicating constant speed.

Tags

NGSS.MS-PS3-1

A distance-time graph shows a line that starts steep and then flattens out. What does this tell you about the object's speed?

• The object is speeding up

• The object is slowing down

• The object is moving at a constant speed

• The object has stopped

Answer explanation

The steep line indicates a high speed, while the flattening suggests a decrease in speed. Therefore, the object is slowing down as it covers less distance over the same time interval.

Tags

NGSS.MS-PS3-1

How would you calculate the average speed of an object using a distance-time graph where the object travels 100 meters in 20 seconds?

Answer explanation

To calculate average speed, use the formula: speed = distance/time. Here, distance is 100 meters and time is 20 seconds. Thus, average speed = 100/20 = 5 m/s, which corresponds to the correct choice.

Tags

NGSS.MS-PS3-1

On a distance-time graph, a line segment is horizontal for a period of time. What does this indicate about the object's motion during that time?

• The object is moving at a constant speed

• The object is accelerating

• The object is decelerating

• The object is not moving

Answer explanation

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

A distance-time graph shows a line that curves upwards. What does this suggest about the object's motion?

• The object is moving at a constant speed

• The object is accelerating

• The object is decelerating

• The object has stopped

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. This rules out constant speed, deceleration, or stopping.

Tags

NGSS.MS-PS3-1

If a distance-time graph shows a line that becomes steeper over time, what can you conclude about the object's speed?

• The object is moving at a constant speed

• The object is accelerating

• The object is decelerating

• The object has stopped

Answer explanation

A steeper line on a distance-time graph indicates that the distance covered by the object is increasing at a faster rate over time, which means the object is accelerating.

Tags

NGSS.MS-PS3-1