Forces

When objects must touch to create a force?

• non-contact

• contact

• applied

Tags

NGSS.MS-PS2-5

Select the contact force

• gravity

• magnetism

• friction

• charge between particles (static electricity)

A box has two forces acting on it. One force is 100 N upward. Another force is 50 N downward. What is the net force on the box?

• 50 N upward

• 100 N upward

• 50 N downward

• 100 N downward

Tags

NGSS.MS-PS2-2

Melanie watched the path a baseball followed after a pitcher threw it. She noticed that the ball traveled horizontally away from the pitcher as well as downward toward the ground. What force caused the ball to accelerate in the downward direction when it was thrown?

• applied force

• air resistance

• gravitational

• electrical

Tags

NGSS.MS-PS2-4

Why are some forces considered to be noncontact forces?

• Objects must be far apart in order to exert a force

• Objects do not have to touch each other to experience a force

• Objects push each other apart to increase the distance between them.

• Objects must be large in size in order to exert a force that is strong enough to notice.

Tags

NGSS.MS-PS2-5

Why is the friction force considered to be a contact force?

• Friction affects only solid objects.

• Friction always acts in the same direction.

• Friction is produced when objects slide past one another.

• Friction acts in a direction opposite to the direction of an object’s motion.

Why is the magnetic force considered to be a noncontact force?

• Magnets must be far apart in order to exert a force.

• Magnets do not have to touch each other to experience a force.

• Magnets push each other apart to increase the distance between them.

• Magnets must be large in size in order to exert a force that is strong enough to notice.

Tags

NGSS.MS-PS2-5

A bird flies at 12.5 meters per second. The wind speed is 4.5 meters per second. What is the speed of the bird when it flies with the wind?

• 12.5 m/s

• 17.0 m/s

• 8.0 m/s

• 4.5 m/s

A bird flies at 12.5 meters per second. The wind speed is 4.5 meters per second. What is the speed of the bird when it flies against the wind?

• 17.0 m/s

• 8.0 m/s

• 12.5 m/s

• 4.5 m/s

What is net force?

• the sum of all the forces acting on an object

• the sum of the contact forces

• the sum of the non contact forces

• the sum is zero, when at rest

Tags

NGSS.MS-PS2-2