After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals

• zero, since no force is necessary to keep it moving.

• twice the force with which it was fired.

• one half the force with which it was fired.

• the same amount of force with which it was fired.

• one quarter the force with which it was fired.

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

Which has more mass, a kilogram of feathers or a kilogram of iron?

• The feathers

• The iron

• Neither—they both have the same mass.

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

• 10 times as much as the force on the 1-kg book.

• zero.

• the same as the force on the 1-kg book.

Tags

NGSS.MS-PS2-4

A player hits a ball with a bat. The action force is the impact of the bat against the ball. What is the reaction to this force?

• The force of the ball against the bat

• The weight of the ball

• Air resistance on the ball

• The grip of the player's hand against the bat

• none of the above

Tags

NGSS.MS-PS2-1

A person is attracted towards the center of Earth by a 440-N gravitational force. The force with which Earth is attracted toward the person is

• 440 N.

• very very small.

• very very large.

Tags

NGSS.MS-PS2-4

Friction is a force that always acts

• perpendicular to an object's motion.

• opposite to an object's motion.

• in the same direction as an object's motion.

The law of inertia applies to

• objects at rest.

• moving objects.

• both moving and nonmoving objects.

One object has twice as much mass as another object. The first object also has twice as much

• velocity.

• gravitational acceleration.

• inertia.

• all of the above

Tags

NGSS.MS-PS3-1

Compared to its weight on Earth, a 10-kg object on the moon will weigh

• the same amount.

• less.

• more.

Tags

NGSS.MS-PS2-4

How does acceleration of an object change in relation to its mass? It is

• directly proportional.

• Acceleration doesn't depend on mass at all.

• inversely proportional.

Tags

NGSS.MS-PS2-2