Unit 8.1 Quiz 1

A student walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. What is the distance in meters?

• 0

• 4

• 6

• 8

• 12

Answer explanation

To find distance, you add up all of the individual distances in each direction.

How far has the ball traveled in the first 3 seconds?

• 0 cm

• about 35 cm

• about 45 cm

• about 90 cm

Answer explanation

How far is a distance question. If you never change direction, you take the final position and subtract the initial position to find the total distance traveled.

Given the position and time data shown, how far did the object travel in the five seconds?

• 25 meters

• 30 meters

• 65 meters

• 85 meters

Answer explanation

If the object never changes direction, you can find the distance by finding the difference between the initial position and the final position.

A radio-controlled car travels in one direction down a straight track. A part of the motion is shown in the top-view diagram. Every minute the car sprays a paint dot on the track to mark its position. How would you describe the motion of the car at t = 4 minutes?

• The car is moving at 5 meters/minute.

• The car is moving at 20 meters/minute.

• The car is speeding up.

• The car is stopped at the 20 meter mark.

Answer explanation

The distance is shorter between 3 and 4 seconds, and longer between 4 and 5 seconds. The distance traveled in the same amount of time is increasing.

Tags

NGSS.MS-PS3-1

What statement describes the object's motion at the point indicated by the dot on the graph?

• The object is not moving.

• The object is moving at a constant speed.

• The object is moving downhill.

• The object is slowing down.

Answer explanation

On a position vs. time graph, a straight diagonal line indicates constant speed.

What is the average speed of an automobile that travels a distance of 30 km in 0.5 h?

• 15 km/h

• 45 km/h

• 60 km/h

• 75 km/h

Answer explanation

Average speed is total distance divided by total time traveled.

How far has the object traveled from the beginning of the motion (t = 0s) to the point indicated by the dot on the graph (t = 2s)?

• 1 meter

• 2 meters

• 2.5 meters

• 3 meters

Answer explanation

At t = 0 sec, the position is 2. At t = 2 sec, the position is 3. The distance traveled is the change in position.

Tags

NGSS.MS-PS3-1

How far did the object travel in the 16 seconds?

• 6 meters

• 8 meters

• 10 meters

• 14 meters

Answer explanation

If the object does not change direction, the distance traveled will be the change in position (ending position minus beginning position).

Tags

NGSS.MS-PS3-1