What Do You Know About Forces?

What is the SI unit of force?

• kilogram

• newton

• meter

• second

Changes in motion are caused by

• nonzero net forces

• balanced forces

• equal and opposite forces

Tags

NGSS.MS-PS2-2

The sum of all forces acting on an object is

• net force

• always balanced

• never balanced

Tags

NGSS.MS-PS2-2

A force is described by its

• strength only

• direction only

• strength and direction

In which situation are the forces operating on an object unbalanced?

• A stack of books rests on a table.

• A car has a constant motion of 60 miles per hour.

• Two sides of a balance both support 20 kg.

• A baseball falls at a faster and faster speed.

Tags

NGSS.MS-PS2-2

The force that one surface exerts on another when two surfaces rub against each other is called

• gravity.

• inertia.

• friction.

• momentum.

When you push a desk that does not move,

• sliding friction occurs.

• static friction occurs.

• fluid friction occurs.

• rolling friction occurs.

Gravity is a force that

• pushes objects away from each other.

• pulls objects toward each other.

• only exists on Earth.

Tags

NGSS.MS-PS2-4

NGSS.MS-PS2-5

Two factors that affect the gravitational attraction between objects are

• mass and distance.

• distance and time.

• force and mass.

• force and time.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

What is mass?

• The measure of the force of gravity on an object.

• The measure of the amount of matter in an object.

• The measure of force that an object exerts on another object.

• Mass is the same as weight.