Ch. 12.1 Forces

A force is defined as a(n) __________ or a(n) __________ that acts on an object. (pages 356–357)

• force, influence

• push, pull

• energy, motion

• mass, weight

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Is the following sentence true or false? A force can act to cause an object at rest to move or it can accelerate an object that is already moving. (p. 356-357)

• True

• False

Tags

NGSS.MS-PS2-2

3. How can a force change the motion of an object that is already moving? (pages 356–357)

• By changing its speed

• By changing its direction

• By changing both speed and direction

• By stopping the object

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

What force causes a 1-kg mass to accelerate at a rate of 1 meter per second each second? (p. 356-357)

• 1 kg/m*s^2

• 1 kg/s

• 1 kg*m

• 1 newton

Tags

NGSS.MS-PS2-2

The overall force acting on an object after all the forces are combined is the __________. (pages 357–358)

• net force

• gravitational force

• frictional force

• applied force

Tags

NGSS.MS-PS2-2

6. How do balanced and unbalanced forces affect the motion of an object? (pages 357–358)

• Balanced forces do not change the motion of an object, while unbalanced forces cause a change in motion.

• Balanced forces cause a change in motion, while unbalanced forces do not change the motion of an object.

• Both balanced and unbalanced forces do not affect the motion of an object.

• Both balanced and unbalanced forces cause a change in motion.

Tags

NGSS.MS-PS2-2

Is the following sentence true or false? Friction is a force that helps objects that are touching move past each other more easily. (p. 359-360)

• True

• False

Select the letters that identify types of friction. (p. 359-360)

• a. rolling

• b. gravity

• c. static

• d. sliding

The friction force that acts on objects that are at rest is _________. (p. 359-360)

• static

• kinetic

• rolling

• sliding

Less force is needed to keep an object moving than to start the object in motion because: (p. 359-360)

• the object has inertia.

• sliding friction is less than the static friction that acts on an object at rest.

• the object gains momentum.

• the force of gravity is reduced.