Motion Quiz

A car approached a stop sign and slowed down from 40 mph to a stop.

This is an example of:

• speed

• velocity

• acceleration

Answer explanation

This scenario illustrates acceleration, as the car decreases its speed from 40 mph to a stop. Acceleration refers to any change in velocity, which includes slowing down.

The baseball was pitched at 100 m/s.

This is an example of:

• speed

• velocity

• acceleration

Answer explanation

The baseball's speed of 100 m/s indicates how fast it is moving, without a specific direction. This is a definition of speed, which measures the rate of motion, unlike velocity, which includes direction.

Tags

NGSS.MS-PS3-1

The school bus traveled north at 55 mph.

This is an example of:

• speed

• velocity

• acceleration

Answer explanation

This is an example of velocity because it includes both speed (55 mph) and direction (north). Velocity is defined as speed with a specified direction, while speed alone does not convey direction.

What is velocity?

• The distance an object travels per unit of time.

• The change in position of an object.

• Speed in a given direction.

• The state in which one objects distance from another is changing.

Answer explanation

Velocity is defined as speed in a given direction, distinguishing it from speed, which is a scalar quantity. This means that velocity not only considers how fast an object is moving but also the direction of that movement.

Speed is defined as -

• Distance between two points

• Amount of force applied

• Time taken to complete a task

• Rate at which an object covers distance

Answer explanation

Speed is defined as the rate at which an object covers distance. It quantifies how quickly an object moves from one point to another, making 'Rate at which an object covers distance' the correct choice.

Acceleration is best defined as -

• the rate of change of velocity with respect to time

• the force applied to an object

• the distance traveled over time

• the speed of an object at a given moment

Answer explanation

Acceleration is defined as the rate of change of velocity with respect to time. This means it measures how quickly an object's speed or direction changes, making it the correct choice among the options provided.

Tags

NGSS.MS-PS2-2

What is the difference between the velocity and the speed of an object?

• Velocity is the change in distance over time, while speed is the change in velocity over time.

• Velocity has a direction associated with it, while speed has no specific direction

• Velocity has no direction associated with it, while speed has a specific direction

• Velocity is the change in speed over time, while speed is the change in distance over time

Tags

112.20.b.6.B

Which is the correct formula to solve for speed?

• speed = time / distance

• speed = distance / time

• speed = distance + time

• speed = distance - time

Answer explanation

The correct formula for speed is speed = distance / time. This means speed is calculated by dividing the distance traveled by the time taken, making this option the only accurate choice among the given answers.

Tags

NGSS.MS-PS3-1

It takes you 20 seconds to walk 10 meters to math class. What is your average speed?

• 2 m/s

• 0.5 m/s

• 200 m/s

• 5 m/s

Answer explanation

To find average speed, use the formula: speed = distance/time. Here, distance = 10 meters and time = 20 seconds. Thus, speed = 10 m / 20 s = 0.5 m/s. The correct answer is 0.5 m/s.

A family traveled at a speed of 45 km/hour to make the 450 km trip to visit relatives. How long did it take the family to reach their destination?

• 8 hours

• 12 hours

• 15 hours

• 10 hours

Answer explanation

To find the time taken, use the formula: time = distance/speed. Here, time = 450 km / 45 km/hour = 10 hours. Thus, the family took 10 hours to reach their destination.