A man of mass 90 kg is standing in an elevator whose cable broke suddenly. IF the elevator falls freely, the force exerted by the floor on the man is

Options

A. 90 N
B. 90 g N
C. 0 N
D. any negative value

Explanation

To solve the problem, we need to analyze the situation of the man standing in a freely falling elevator.

### Step-by-Step Solution:

1. **Identify the Mass of the Man**:
The mass of the man is given as 90 kg.

2. **Understand the Situation**:
The elevator is in free fall, meaning it is falling under the influence of gravity without any resistance. In this scenario, both the elevator and the man inside it are accelerating downwards at the same rate due to gravity.

3. **Determine the Forces Acting on the Man**:
Normally, when standing on a surface, the man would experience a downward gravitational force (weight) given by \( W = mg \), where \( g \) is the acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \)). However, in free fall, the man does not experience any normal force from the floor of the elevator.

4. **Calculate the Weight of the Man**:
The weight of the man can be calculated as:
\[ W = mg = 90 \, \text{kg} \times 9.81 \, \text{m/s}^2 = 882.9 \, \text{N} \]
However, this force is acting downwards.

5. **Normal Force in Free Fall**:
In free fall, the normal force exerted by the floor on the man is equal to zero because both the man and the elevator are accelerating downwards at the same rate. There is no contact force acting on the man from the floor.

6. **Conclusion**:
Since the elevator is falling freely, the force exerted by the floor on the man is:
\[ \text{Force} = 0 \, \text{N} \]

### Final Answer:
The force exerted by the floor on the man is **0 Newton**.

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