8.6B

Acceleration of an object happens when it ________

• slows down
• speeds up
• changes direction
• all of the these

When a car goes around a corner at 20 mph, why do we say it  accelerates?

• The car is accelerating because of the velocity is constant
• The car accelerates because it's going 20 mph
• Cars always accelerate when they are in motion
• The car is accelerating because it's changing direction

The correct equation to calculate speed is

• distance ÷ time
• time/distance
• distance x time
• distance/time²

The unit meters per second (m/s) is used for which of the following?

• Distance
• Time
• Speed
• Acceleration

Which of the following best describes the velocity of an object?

• 100 miles/hour south
• 65 miles
• 20 miles east
• 40 meters per second

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

• Velocity is a change in distance over time, speed is the change in direction 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.

Which car is accelerating?

• A car traveling west at a speed of 80 mph
• A  car that goes around a curve at a constant speed
• A car that is stopped at a stop sign
• A car that is moving at a constant speed of 60mph

The vehicles pictured are all traveling at a speed of 15 m/s but only the truck has a changing velocity. The truck has a changing velocity because -

• it accelerates faster than the other 2 vehicles
• it is traveling in the opposite direction from the other 2 vehicles
• it is traveling on a curve in the road
• it needs a large amount of force to move