Which of the following is not an example of the force of gravity ?

Options

A. a leaf falling from a tree
B. a boy pushing a cart on a level plane
C. a diver jumping into a swimming pool
D. a stone falling from the top of a cliff.

Answer

To determine which of the following is not an example of the force of gravity, we need to analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Force of Gravity**:
- The force of gravity is an attractive force that pulls objects towards each other. It acts on all objects with mass, and it is always directed towards the center of the larger mass (like the Earth).

2. **Evaluate Each Option**:
- **Option 1: A leaf falling from a tree**:
- When a leaf falls, it is being pulled down towards the Earth due to gravity. This is an example of the force of gravity.
- **Option 2: A boy pushing a cart on a level plane**:
- In this scenario, the boy is applying a horizontal force to move the cart. There is no gravitational pull involved in the movement of the cart in this context. Therefore, this is not an example of the force of gravity.
- **Option 3: A driver jumping into a swimming pool**:
- When a driver jumps, gravity pulls them down towards the pool. This is also an example of the force of gravity.
- **Option 4: A stone falling from the top of a cliff**:
- Similar to the leaf, when a stone falls, it is being pulled down by the Earth's gravity. This is another example of the force of gravity.

3. **Conclusion**:
- Based on the analysis, the option that is not an example of the force of gravity is **Option 2: A boy pushing a cart on a level plane**.

### Final Answer:
**Option 2: A boy pushing a cart on a level plane** is not an example of the force of gravity.

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