Unit 4 Pre-Assessment

Which two factors affect the gravitational force between two objects?

• force and size

• size and distance

• mass and distance

• mass and force

Tags

NGSS.MS-PS2-4

If Alonzo wished to determine how the size of a force affected the motion of an object, which of the following would be the best strategy for his experiment?

• propel several toy cars of different shapes and designs across a surface using a rubber band

• propel a toy car across flat and sloped surfaces using a variety of objects, including rubber bands

• propel three toy cars of different masses across a flat surface using a rubber band stretched to the same degree each time

• propel a toy car across a flat surface using a rubber band stretched to three different degrees

Tags

NGSS.MS-PS2-2

A group of students measured the amount of force needed to move a weight across a dry plastic tabletop. Then they poured some water on the table and repeated the experiment on the wet surface. The students found that less force was needed to start the weight moving on the wet surface than on the dry surface. What caused the difference in the results of the two experiments?

• a change in the amount of gravitational force on the weight

• a change in the mass of the weight used in the experiment

• a change in the friction between the weight and the scale used to measure force

• a change in the friction between the weight and the surface

Tags

NGSS.MS-PS2-2

Ms. Stockton’s class makes a ramp. Her students release a toy car and let it roll down the ramp. They measure how long it takes the toy car to travel 1 m past the end of the ramp. Which of the following reasons explains why the students need to have several trials of releasing the car before they analyze the results?

• They may want to move the ramp each time.

• The carpet on the floor may have slowed down the car.

• They may want to try pushing the car instead of releasing it.

• Someone could have been distracted and might not have stopped the stopwatch right away.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-1

NGSS.MS-PS3-5

Which of the following is the best way of stating Newton’s first law of motion?

• Objects at rest don’t move unless an unbalanced force acts on them, and objects in motion don’t slow down, speed up, stop, or turn unless a force makes them do so.

• Objects in space move randomly and unpredictably because no forces act on them.

• Once an object at rest begins to move, it will soon begin to slow down, turn, or stop.

• Balanced forces cause an object to move, and unbalanced forces cause it to stop moving.

According to Newton’s third law of motion, what happens when one object applies a force to a second object?

• The second object accelerates.

• The first object changes the mass of the second object.

• The second object applies an equal, opposite force to the first object.

• The first object and the second object begin to move, or they change the way they are moving.

Tags

NGSS.MS-PS2-1

The following table shows the results of an experiment in a science lab. Ten seconds after the experiment started, a ball was pushed across the floor and was not touched again.

Which statement could explain why the ball did not roll as far between 30 sec and 40 sec as it rolled between 20 sec and 30 sec?

• The ball slowed because of the force of friction.

• The ball slowed because of the effects of gravity.

• The ball slowed because the person did not push it hard enough.

• The ball slowed because the person pushing it stopped exerting force.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-1

Jevon pulls on the handle of a wagon containing 50 pounds of gardening soil, but the wagon does not move. Which of the following actions would be most likely to start the wagon in motion?

• Increase the amount of mass in the wagon.

• Increase the amount of force on the handle.

• Maintain the same amount of force on the handle.

• Change the force on the handle from a pull to a push.

Tags

NGSS.MS-PS2-2

Which of the following is the best way of stating Newton’s first law of motion?

• Objects in space move randomly and unpredictably because no forces act on them.

• Once an object at rest begins to move, it will soon begin to slow down, turn, or stop.

• Balanced forces cause an object to move, and unbalanced forces cause it to stop moving.

• Objects at rest don’t move unless an unbalanced force acts on them, and objects in motion don’t slow down, speed up, stop, or turn unless a force makes them do so.

According to Newton’s second law of motion, which two factors determine an object’s acceleration?

• the speed of the object and the power of inertia on the object

• the shape of the object and the material from which the object is made

• the mass of the object and the amount of force applied to the object

• the strength of gravity as it is applied to the object and the weight of the object

Tags

NGSS.MS-PS2-2