Motion Matters: Speed and Acceleration Quiz

Which of the following is a scalar quantity?

• Velocity

• Displacement

• Speed

• Acceleration

Answer explanation

Speed is a scalar quantity as it only has magnitude and no direction. In contrast, velocity, displacement, and acceleration are vector quantities, which include both magnitude and direction.

What is the SI unit for measuring speed?

• m/s

• kg

• N

Answer explanation

The SI unit for measuring speed is meters per second (m/s). This unit expresses the distance traveled in meters for each second of time, making it the standard measurement for speed.

Tags

NGSS.MS-PS3-1

Which of the following best describes velocity?

• The rate at which an object covers distance

• The rate at which an object changes its position in a specific direction

• The total path length traveled

• The amount of matter in an object

Answer explanation

Velocity is defined as the rate at which an object changes its position in a specific direction, distinguishing it from speed, which only considers distance covered without direction.

If a car travels 100 meters in 5 seconds, what is its average speed?

• 20 m/s

• 50 m/s

• 10 m/s

• 25 m/s

Answer explanation

To find average speed, divide distance by time. Here, average speed = 100 meters / 5 seconds = 20 m/s. Thus, the correct answer is 20 m/s.

Which of the following is a vector quantity?

• Distance

• Speed

• Displacement

• Time

Answer explanation

Displacement is a vector quantity as it has both magnitude and direction, representing the shortest path from the initial to the final position. In contrast, distance and speed are scalar quantities, and time is not a vector.

What does acceleration measure?

• How fast an object is moving

• The change in velocity per unit time

• The total distance traveled

• The amount of force applied

Answer explanation

Acceleration measures the change in velocity per unit time, indicating how quickly an object's speed or direction is changing. This makes 'The change in velocity per unit time' the correct choice.

If a runner moves 60 meters east in 10 seconds, what is her average velocity?

• 6 m/s east

• 6 m/s west

• 0.17 m/s east

• 600 m/s east

Answer explanation

Average velocity is calculated as total displacement divided by total time. Here, the runner moves 60 meters east in 10 seconds, so average velocity = 60 m / 10 s = 6 m/s east, making '6 m/s east' the correct choice.

Which of the following is NOT a unit of acceleration?

• m/s

Answer explanation

Acceleration is defined as the change in velocity over time, measured in units like m/s² or km/h². The unit m/s represents velocity, not acceleration, making it the correct choice for the option that is NOT a unit of acceleration.

A skateboarder travels 40 meters north, then 30 meters south. What is the total distance traveled?

• 10 meters

• 70 meters

• 40 meters

• 30 meters

Answer explanation

The skateboarder travels 40 meters north and then 30 meters south. The total distance is the sum of both segments: 40 + 30 = 70 meters. Therefore, the correct answer is 70 meters.

Which of the following best describes displacement?

• The total length of the path traveled

• The amount of positional change an object has

• The rate of change of speed

• The amount of time taken to travel

Answer explanation

Displacement refers to the amount of positional change an object has, measuring the shortest distance from the initial to the final position, regardless of the path taken. This distinguishes it from total path length.