Normal Reaction Force in Lifts

The video tutorial explains the forces acting on a person in a lift, focusing on the normal reaction force and its relation to weight. It covers scenarios of the lift being stationary, accelerating upwards, moving with constant velocity, and decelerating. The tutorial also discusses the concept of weightlessness when the lift is in free fall due to a snapped cable, illustrating how the normal force changes with different states of motion.

What does the normal reaction force represent when a person stands on a weighing scale?

• The force exerted by the person on the scale

• The gravitational force acting on the person

• The upward force exerted by the scale

• The weight of the person

When a lift accelerates upwards, how does the normal reaction force compare to the person's weight?

• It is less than the weight

• It is zero

• It is equal to the weight

• It is more than the weight

What happens to the normal reaction force when the lift moves upwards with constant velocity?

• It becomes zero

• It becomes greater than the weight

• It remains equal to the weight

• It becomes less than the weight

During upward deceleration, how does the normal reaction force change?

• It increases

• It decreases

• It remains constant

• It becomes zero

When a lift accelerates downwards, what is the relationship between the normal reaction force and the weight?

• The normal reaction force is zero

• The normal reaction force is greater than the weight

• The normal reaction force is equal to the weight

• The normal reaction force is less than the weight

If a lift moves downwards with constant velocity, what happens to the normal reaction force?

• It becomes less than the weight

• It becomes greater than the weight

• It remains equal to the weight

• It becomes zero

How does the normal reaction force change during downward deceleration?

• It becomes zero

• It increases

• It decreases

• It remains constant

What is the effect on the normal reaction force when the lift cable snaps and the lift is in free fall?

• The normal reaction force becomes zero

• The normal reaction force increases

• The normal reaction force decreases

• The normal reaction force remains constant

What term describes the condition when the normal reaction force is zero during free fall?

• Weight gain

• Weightlessness

• Weight stability

• Weight increase

In the context of the video, what does 'free fall' imply about the forces acting on a person?

• Only gravitational force acts on the person

• No forces act on the person

• The person experiences an upward force

• The person experiences a downward force greater than gravity