The weight of a body will appear to be zero when

Options

A. a.It is kept at the centre of the earth
B. b.It is freely falling
C. c.It is inside the satellites orbiting around the earth
D. d.All of these

Answer

To determine when the weight of a body appears to be zero, we can analyze the three scenarios provided in the question.

### Step-by-Step Solution:

1. **Weight at the Center of the Earth**:
- At the center of the Earth, the gravitational force acting on a body is zero. This is because, as we move towards the center, the gravitational pull from the surrounding mass of the Earth cancels out.
- Mathematically, the gravitational acceleration \( g \) at the center can be derived from the formula:
\[ g = \frac{GM}{r^2} \]
where \( G \) is the gravitational constant, \( M \) is the mass of the Earth, and \( r \) is the radius. At the center, \( r = 0 \), hence \( g = 0 \).
- Therefore, the weight \( W = mg = 0 \).

2. **Weight of a Freely Falling Body**:
- When a body is in free fall, it is accelerating downwards due to gravity, and there are no contact forces acting on it (like normal force).
- In this case, the only force acting on the body is its weight \( mg \), but since it is falling freely, it does not experience any normal force from a surface.
- Thus, the effective weight appears to be zero because the body is in a state of weightlessness.

3. **Weight Inside a Satellite Orbiting the Earth**:
- A satellite in orbit is in a continuous state of free fall towards the Earth, but it has enough tangential velocity to keep missing it.
- Inside the satellite, everything is in free fall, including any objects. Therefore, the normal force acting on the objects inside the satellite is also zero.
- Consequently, the weight of any object inside the satellite appears to be zero, as there is no contact force acting on it.

4. **Conclusion**:
- Since in all three scenarios (A, B, and C), the weight of the body appears to be zero, the correct answer is:
\[ \text{D) All of these} \]