Understanding Normal Force

The video tutorial explains the concept of normal force, a force perpendicular to a surface, and its role in maintaining equilibrium. It uses examples of boxes on surfaces to illustrate how normal force works. The tutorial also covers how to increase or decrease normal force by applying additional forces, such as downward or upward forces. It provides calculations for normal force on horizontal surfaces and when additional forces are applied. The video further explores the effect of tension on normal force and explains how to calculate normal force on an inclined plane using the cosine of the angle of incline.

What is a normal force in relation to a surface?

• A force perpendicular to the surface

• A force parallel to the surface

• A force that acts at an angle to the surface

• A force that is equal to the weight of the object

How does a normal force act on an inclined plane?

• It acts at a 45-degree angle to the incline

• It acts in the same direction as gravity

• It acts perpendicular to the incline

• It acts parallel to the incline

What happens to the normal force when a downward force is applied to an object on a surface?

• The normal force decreases

• The normal force remains the same

• The normal force increases

• The normal force becomes zero

How can you decrease the normal force on an object?

• By applying a downward force

• By increasing the mass of the object

• By applying an upward tension force

• By reducing the gravitational force

What is the normal force on a 20 kg block resting on a horizontal surface?

• 9.8 N

• 0 N

• 20 N

• 196 N

If a 300 N downward force is applied to a 20 kg block, what is the new normal force?

• 0 N

• 300 N

• 496 N

• 196 N

What happens to the normal force if an upward tension force exceeds the weight of the object?

• The normal force becomes negative

• The normal force becomes zero

• The object remains in equilibrium

• The normal force increases

How is the normal force on an incline calculated?

• mg divided by the angle

• mg times sine of the angle

• mg times cosine of the angle

• mg plus the angle

What happens to the normal force as the angle of an incline increases?

• It becomes zero

• It increases

• It remains constant

• It decreases

What does a negative normal force indicate?

• The object is moving downwards

• The object is accelerating upwards

• The object is at rest

• The object is in contact with the surface