Force and Motion Review

Daylon’s family just bought a new puppy, and Daylon decided to take him for a walk. He put the puppy in a wagon and pulled the wagon along the sidewalk. From which of these reference points does the puppy appear to be moving?

• Daylon

• the wagon

• the sidewalk

• the puppy’s collar

Two school classes are playing tug-of-war with a rope. One class pulls on the rope with a 75 N force to the left, the other pulls with a 40 N force to the right. Which two statements describe this situation?

• The forces are balanced, and the rope does not move.

• The forces are unbalanced, and the rope will move to the left.

• The net force on the rope is 115 N to the right.

• The net force on the rope is 35 N to the left.

Tags

NGSS.MS-PS2-2

You might have noticed that a feather falls slowly toward the ground, while a ball falls rapidly. Which statement correctly explains the motion of these objects?

• The ball does not experience fluid friction as it falls.

• Gravity is the only force acting on the feather and the ball.

• The acceleration of the ball and feather are the same.

• The feather experiences more fluid friction than the ball.

Tags

NGSS.MS-PS3-1

Nicki rides her bike at a constant speed for 6 km. That part of her ride takes her 1 h. She then rides her bike at a constant speed for another 9 km. That part of her trip takes her 2 h. What is her average speed?

• 3.00 km/h

• 5.00 km/h

• 5.25 km/h

• 7.50 km/h

According to Newton’s first law, what explains why the puppy’s food bowl moves across the room every morning?

• According to Newton’s first law, the bowl has inertia.

• According to Newton’s first law, the dog applied force to the bowl to move it.

• According to Newton’s second law, an action force was applied to the bowl.

• According to Newton’s third law, the bowl applied a reaction force to the puppy.

Nikhil bought a large plant in a planter for his mother. He took it home and pushed it around his living room until he found a good location for it near the window. After he watered the plant, he was very surprised how difficult it was to push the planter. Based on Newton’s second law, why does it become more difficult to move the planter? Choose the three statements that apply.

• With the water, the planter had more mass and more inertia.

• Nikhil had to apply more force to produce the same acceleration.

• Increased inertia means that less force is needed to move the planter.

• If Nikhil used the same amount of force, the acceleration of the moving planter would be less after adding the water.

Tags

NGSS.MS-PS2-2

Teresa did a trick in which she placed dishes on a tablecloth placed on a card table. She pulled quickly on the tablecloth, and it came off the table, leaving the dishes behind on the table. The inertia of the dishes kept them on the table according to which law?

• Newton's first law

• Newton's second law

• Newton's third law

• Law of universal gravitation

When Teresa pulled on the tablecloth with an action force, the tablecloth exerted a reaction force on her, as explained by which law?

• Newton's first law

• Newton's second law

• Newton's third law

• Law of conservation of energy

The tablecloth moved when Teresa applied force to it, as explained by which law?

• Newton's first law

• Newton's second law

• Newton's third law

• Law of universal gravitation

Pam’s family is clearing some land, and there is a large boulder sitting on top of the ground. Even with the entire family pushing on it, they cannot move it. Which type of friction exists between the boulder and the ground?

• fluid

• rolling

• sliding

• static