Forces and Motion Review

What is a **balanced force**?

• A force that causes an object to speed up

• A force that causes an object to change direction

• When two or more forces acting on an object cancel each other out

• When only one force acts on an object

What is **friction**?

• A force that pulls objects toward the center of the Earth

• A force that opposes the motion of an object as it moves across a surface

• A force that pushes two objects apart

• A force that keeps planets in orbit

Which of the following is the **first step** in the engineering design process?

• Build a prototype

• Test the solution

• Define the problem

• Improve the design

Tags

NGSS.MS-ETS1-1

What happens to an object when the forces acting on it are **unbalanced**?

• The object stays completely still

• The object changes its motion

• The object disappears

• The object loses all its weight

Tags

NGSS.MS-PS2-2

What is **net force**?

• The heaviest force acting on an object

• The force of gravity on an object

• The overall force on an object after all forces are combined

• The force that stops an object from moving

Tags

NGSS.MS-PS2-2

Tags

NGSS.MS-PS2-2

Tags

NGSS.MS-PS2-2

A sled is sliding on **ice** versus sliding on **rough pavement**. On which surface will the sled travel farther before stopping, and why?

• Rough pavement, because it has less friction

• Ice, because it has less friction

• Ice, because it has more friction

• Rough pavement, because it has more gravity

Tags

NGSS.MS-PS2-2

During the engineering design process, why is the **testing step** important?

• It allows engineers to skip the building step

• It helps engineers find out if their design solves the problem and what needs to be improved

• It is used only to show the design to other people

• It replaces the need to define the problem

Tags

NGSS.MS-ETS1-2

NGSS.MS-ETS1-3

NGSS.MS-ETS1-4

A toy car rolls across a **carpet** and a **smooth tile floor**. Which surface creates more friction, and how does that affect the car's motion?

• Tile floor creates more friction, so the car moves faster on carpet

• Carpet creates more friction, so the car slows down faster on carpet

• Both surfaces create the same friction, so the car moves the same on both

• Carpet creates less friction, so the car slows down faster on tile