Module K Unit #1 Test

Why is friction force considered a contact force?

Choose the correct answer.

• Friction affects only solid objects.

• Friction always acts in the same direction.

• Friction is produced when objects slide past one another.

• Friction acts in a direction opposite to the direction of an object’s motion.

What is gravity?

• a contact force

• a frictional force

• • a magnetic force

• • a noncontact force

Tags

NGSS.MS-PS2-5

Melanie watched the path a baseball followed after a pitcher threw it. She noticed that the ball traveled horizontally away from the pitcher as well as downward toward the ground. What force caused the ball to accelerate in the downward direction when it was thrown?

• applied force

• • air resistance

• • electrical force

• • gravitational force

Tags

NGSS.MS-PS2-4

Which pair of objects has the largest gravitational force?

• marble and car

• marble and baseball

• • car and bowling ball

• There is no gravitational force between any of these pairs of objects.

Tags

NGSS.MS-PS2-4

NGSS.MS-PS2-5

Sean is moving heavy furniture by sliding it across the floor. He puts a blanket underneath the furniture. Why did this help him?

• The blanket protects the side of the furniture from bumping against the wall.

• • The blanket reduces the gravitational force between the furniture and the floor.

• • The friction is larger between the blanket and the floor than between the furniture and the floor.

• • The friction is smaller between the blanket and the floor than between the furniture and the floor.

Two basketballs are sitting 1 m apart and are not moving. Which best explains why the gravitational force does not cause them to move?

• No gravitational force exists between the two objects because they are not touching.

• The gravitational force between the two objects is weak because they are 1 m apart.

• No gravitational force exists between the two objects because their masses are small.

  
  

• • The gravitational force between the two objects is weak because their masses are small.

Tags

NGSS.MS-PS2-4

Planets A and B are both the same size, but planet B has three times the mass of planet A. How does the weight of an object compare on the two planets?

• The weight of an object is the same on both planets.

• • The weight of an object is three times larger on planet A.

• • The weight of an object is three times larger on planet B.

• • The weight of an object will depend on more factors than just the weight and size of the planet.

Tags

NGSS.MS-PS2-4

Jessica is comparing two balls. One ball has a mass of 1 kg, and the other has a mass of 2 kg. She pushes each with a force of 100 N. How do the accelerations of the two balls compare?

• • The 1 kg ball accelerates the same as the 2 kg ball.

• • The 1 kg ball accelerates half as much as the 2 kg ball.

• The 1 kg ball accelerates twice as much as the 2 kg ball.

• The 1 kg ball accelerates four times as much as the 2 kg ball.

Tags

NGSS.MS-PS2-2

When two objects having different masses collide, they move away from each other at different speeds. Which is true of the forces exerted at the moment of impact?

• • The forces exerted when they collide are equal and opposing.

• • The forces exerted when they collide are unequal and opposing.

• The forces exerted when they collide are equal and in the same direction.

• • The forces exerted when they collide are unequal and in the same direction.

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NGSS.MS-PS2-1

Look at the diagram of forces acting on an object.

The picture shows a push and a pull acting on a box of books sitting on the floor. What is the net force toward the right on the box?

• 0 N

• • 50 N

• • 100 N

• • 2,500 N

Tags

NGSS.MS-PS2-2