Quiz#4 Acceleration and Momentum

The rate that a car's velocity changes is its

• speed

• force

• gravity

• acceleration

Acceleration is defined as the CHANGE in 

• the time it takes for one place to move to another place. 

• the mass of an object divided by the time interval.

• the distance divided by the time interval 

• the velocity divided by the time interval 

A negative acceleration means that an object is _____. 

• not accelerating
• not moving
• speeding up 
• slowing down 

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

In which of the following cases does a car have zero acceleration?

• A car speeding up after a stoplight turns green.

• A car slowing down when it approaches a stop sign.

• A car set on cruise control so that is maintains 45 mi/hr.

• A car turning a curve at a constant speed.

The SI unit for acceleration is

• mph
• ft/sec²
• m/s²

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 box sliding down an inclined plane attains a velocity of 27 m/s in 3 seconds from rest.  Find the acceleration.

• 30 m/s
• 24 m/s²
• 9 m/s²
• 81 km/hr

The picture of the position vs. time graph shows an object that is...

• accelerating/speeding up
• moving at a constant speed 
• not moving 
• accelerating/slowing down. 

Determine the motion of the car.

• at rest 
• moving at constant speed
• speeding up
• slowing down