Exploring Normal and Friction Forces

What is the normal force in relation to a horizontal surface?

• A force that only acts on vertical surfaces

• A force at a 45-degree angle to the surface

• A force perpendicular to the surface

• A force parallel to the surface

How does the normal force behave on a banked surface?

• It points perpendicular to the surface

• It points parallel to the surface

• It points at a random angle

• It does not act on banked surfaces

What happens to the normal force when the coordinate system is rotated?

• It changes direction

• It disappears

• It remains perpendicular to the surface

• It becomes parallel to the surface

Why can't the weight force equal the normal force on a banked surface?

• Because they are not parallel

• Because they are the same force

• Because the normal force does not act on banked surfaces

• Because the weight force is always greater

What is the role of static friction?

• To reduce the weight of the object

• To increase the normal force

• To counter the applied force when the object is not moving

• To accelerate the object

What symbol is usually used to represent static friction?

• A circle

• A squiggly F with a subscript 's'

• An arrow

• A straight line

What happens to the net force when an object starts to move?

• It disappears

• It does not equal zero

• It remains constant

• It becomes zero

Tags

NGSS.HS-PS2-1

What is kinetic friction?

• The force that acts when an object is not moving

• The force that decreases the normal force

• The force that increases the weight of the object

• The force that acts when an object is moving

When does the force of kinetic friction equal the pushing force?

• When the object is accelerating

• When the object is at rest

• When the object is moving at a constant speed

• When the object is falling

What happens to the net force when an object moves at a constant speed?

• It decreases

• It becomes negative

• It increases

• It becomes zero