Force and Matter

A car starts at point X and travels 20 km north to point Y in 10 minutes. What is the displacement of the car?

• 0 km, because the car’s motion canceled out its displacement

• 2 km north, because the car’s displacement is dependent on time from start to finish

• 20 km north, because the car’s direction remained constant throughout its travel

• 40 km north, because the car’s displacement is twice the distance traveled

Two identical cars, car X and car Y, are both traveling in the same direction at different speeds. As car Y passes car X, the passengers in car X feel as if they are moving backwards. Why do the passengers perceive their motion this way?

• because of car Y’s displacement

• because of car Y’s negative acceleration

• because of the passengers’ momentum in car X

• because of the passengers’ frame of reference in car X

A boy rides his bike 5 km east from his home and then returns. Why is there a difference between his total distance traveled and his displacement?

• Because when he returned home, his total distance was reduced by half

• because when he returned home, his displacement was doubled

• because when he returned home, his displacement was zero

• because when he returned home, his total distance was zero

The graph below shows the positions of three cars over time. Based on the graph, what is true about these cars?

• A. Car 1 and 3 are moving, unlike Car 2.

• B. Car 2 and 3 are increasing in speed, unlike Car 1.

• C. They all have the same speed when t = 6 s.

• D. They all have a negative acceleration.

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After 100 minutes, how does the motion of bicyclist M compare to the other bicyclists?

• A. Bicyclist M paused in the middle of the travel, unlike the other bicyclists.

• B. Bicyclist M maintained a constant speed, unlike the other bicyclists.

• C. Bicyclist M traveled with a greater speed than the other bicyclists.

• D. Bicyclist M traveled a shorter distance than the other bicyclists.

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NGSS.MS-PS3-1

A few seconds after opening up a parachute, a skydiver reaches terminal velocity. Why does the skydiver eventually reach terminal velocity?

• because the parachute increases the speed of the skydiver

• because the surface area of the parachute decreases when it is opened

• because the force of air resistance equals the weight of the skydiver

• because the force of gravity on the skydiver is greater than the force of air resistance

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How does gravity affect an object as it falls?

• It prevents friction from acting on the object.

• It determines the rate at which the object falls.

• It changes the total mass of the object as it falls.

• It reduces the weight of the object as it gets closer to sea level.

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Why does the weight of a solid object on the moon change when the same object is brought to Earth?

• because the density of the object on the moon is different

• because the effects of air resistance are greater on the moon

• because the mass of the object changes between the moon and Earth

• because the force of gravity on the moon is different from that on Earth

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NGSS.MS-PS2-4

What is the weight, in newtons, of a 52-kilogram object on Earth’s surface? (Note: The acceleration due to gravity is 9.8 m/s².)

• 449 newtons

• 510 newtons

• 532 newtons

• 561 newtons

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An object is dropped from rest 1.0 m above Earth’s surface. Which choice best describes the speed and weight of the object while it is in free fall?

• The object’s speed decreases, and its weight remains the same.

• The object’s speed increases, and its weight remains the same.

• The object’s speed decreases, and its weight decreases.

• The object’s speed increases, and its weight decreases.

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NGSS.MS-PS2-2

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