Acceleration

Which of the following is a unit for acceleration?

• km/s
• m/s²
• mi/hr
• ft

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

Acceleration is defined as the CHANGE in 

• time it takes for one place to move to another place. 
• velocity of an object.
• distance divided by the time interval 
• velocity divided by the time interval 

Acceleration only takes place when things speed up. 

• True
• False

In each of the following cases, determine where the car has no acceleration ?

• A car shortly after a stoplight turns green.
• A car approaching a red light
• A car with the cruise control set at 80 km/h
• A car turning a curve at a constant speed

A roller coasters accelerates from an initial velocity of 6.0 m/s to a final velocity of 70 m/s over 4 seconds.  What's the acceleration?

• 24 m/s²
• 18 m/s²
• 16 m/s²
• 16 m/s

A dog runs with an initial speed of 7.5 m/s on a waxed floor.  It slides to a stop in 15 seconds.  What is the acceleration?

• -7.5 m/s
• -7.5 m/s²
• -0.5 m/s²
• 7.5 mi//hr

A drag racer accelerated from 0 m/s to 200 m/s in 5 s.  What was the acceleration?

• 0 m/s
• 40 m/s²
• -40 m/s²
• 40 m/s

Acceleration can be classified as _______________

• Speeding up
• Slowing Down
• Changing directions
• All of the above

A golf ball accelerates off a tee at 15m/s², changing its velocity from 0m/s to 50 m/s down the fairway. How long did it take the golf ball to accelerate?

• 750 seconds
• 35 seconds
• 0.3 seconds
• 3.3 seconds