Motion and Forces Concept Check

Which statement correctly compares static friction and sliding friction?

• Static friction is always less than sliding friction.

• Sliding friction prevents objects from starting to move.

• Static friction acts on objects at rest, while sliding friction acts on objects in motion.

• Both static and sliding friction act only on liquids.

What is one effect of air resistance on falling objects?

• Air resistance causes objects to fall faster than in a vacuum.

• Air resistance slows down falling objects.

• Air resistance has no effect on falling objects.

• Air resistance makes objects heavier.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

What are the two main characteristics of a force that make it a vector quantity?

• Size and direction

• Mass and volume

• Speed and distance

• Temperature and pressure

In which SI unit is force measured?

• Newtons (N)

• Joules (J)

• Watts (W)

• Meters (m)

A student pushes a box across the floor. Explain why this action is considered applying a force, and identify the two characteristics that describe this force.

• It is a force because it is a push; the two characteristics are size (strength of the push) and direction (direction of the push)

• It is not a force because the box is not moving; the two characteristics are color and shape

• It is a force because the box is heavy; the two characteristics are mass and volume

• It is not a force because the student is not pulling; the two characteristics are speed and distance

What is the definition of net force?

• The force that acts on an object due to gravity

• The force that combines when two or more forces act on an object

• The force that is always equal to zero

• The force that only acts in one direction

Tags

NGSS.MS-PS2-2

Which of the following best describes balanced forces?

• Forces that are equal in size and act in the same direction

• Forces that are unequal in size and opposite in direction

• Forces that are equal in size and opposite in direction

• Forces that only act on moving objects

What is the net force when two forces of 45 N each act in opposite directions on an object?

• 90 N

• 45 N

• 0 N

• 22.5 N

Tags

NGSS.MS-PS2-2

Refer to the diagram showing a block with two arrows labeled 45 N pointing in opposite directions. What does this diagram illustrate?

• Unbalanced forces causing motion

• Balanced forces resulting in no net force

• Gravitational force only

• Frictional force only

What happens when unbalanced forces act on an object?

• The object will not move.

• The object will move in the direction of the larger force.

• The forces cancel each other out.

• The object will move in the direction of the smaller force.

Tags

NGSS.MS-PS2-2