The correct option is **A. The gravitational field strength decreases with distance from the object and is strongest at the surface.** ### Detailed Explanation: 1. **Understanding Gravitational Fields:** - A gravitational field is a region around a massive object where other masses experience a force due to gravity. The strength of this field is determined by the mass of the object and the distance from it. 2. **Gravitational Field Strength:** - The gravitational field strength (denoted as \( g \)) at a distance \( r \) from a mass \( M \) can be calculated using the formula: \[ g = \frac{GM}{r^2} \] where \( G \) is the gravitational constant (\( 6.674 \times 10^{-11} \, \text{N m}^2/\text{kg}^2 \)). - From this formula, we can see that as the distance \( r \) increases, the gravitational field strength \( g \) decreases because it is inversely proportional to the square of the distance. This means that the further you are from the mass, the weaker the gravitational pull you will experience. 3. **Why Option A is Correct:** - Option A correctly states that the gravitational field strength decreases with distance from the object and is strongest at the surface. This aligns with the formula we discussed, as at the surface of a massive object (like a planet), the distance \( r \) is at its minimum, resulting in the maximum gravitational field strength. ### Analysis of Other Options: - **Option B: The gravitational field is uniform and has the same strength in all directions around the object.** - This statement is incorrect because a gravitational field around a massive object is not uniform. The strength of the gravitational field varies with distance from the object. For example, the gravitational field is stronger closer to the object and weaker further away, which contradicts the idea of uniformity. - **Option C: The gravitational field lines point away from the object, indicating a repulsive force.** - This statement is also incorrect. Gravitational field lines actually point towards the massive object, indicating an attractive force. This is because gravity pulls objects towards the mass, not pushes them away. If the lines pointed away, it would suggest a repulsive force, which is not the case for gravity. - **Option D: The gravitational field strength increases as the distance from the object increases.** - This statement is fundamentally wrong. As we established earlier, the gravitational field strength decreases with increasing distance from the object. Therefore, this option contradicts the basic principles of gravitational fields. ### Common Pitfalls: - Students often confuse gravitational fields with electric fields, where the latter can have repulsive forces. Remember that gravity is always attractive. - Misunderstanding the concept of uniform fields can lead to incorrect assumptions about how gravity behaves at different distances. ### Revision Summary: - The gravitational field strength decreases with distance from a massive object and is strongest at the surface. - The formula for gravitational field strength is \( g = \frac{GM}{r^2} \). - Gravitational field lines point towards the mass, indicating an attractive force. - Gravitational fields are not uniform; they vary with distance from the mass.