When air resistance is taken into account while dealing with the motion of the projectile which of the following properties of the projectile, shows an increases?

Options

A. range
B. maximum height
C. speed at which it strikes the ground
D. the angle at which the projectile strikes the ground

Explanation

To analyze the motion of a projectile considering air resistance, we need to understand how various properties of the projectile are affected. The question asks which property shows an increase when air resistance is taken into account.

### Step-by-Step Solution:

1. **Understanding the Forces**:
- In projectile motion, the primary force acting on the projectile is gravity (G). When air resistance is considered, an additional force acts opposite to the direction of motion, which we can denote as air thrust force (A).
- The net force acting on the projectile will be the gravitational force minus the air resistance.

2. **Effect on Range**:
- The range (R) of a projectile is given by the formula \( R = \frac{u^2 \sin(2\theta)}{g} \).
- When air resistance is present, it effectively increases the acceleration acting against the projectile, thus reducing the range. Therefore, the range decreases.

3. **Effect on Maximum Height (Hmax)**:
- The maximum height (Hmax) is given by \( H_{max} = \frac{u^2 \sin^2(\theta)}{2g} \).
- Similar to the range, the presence of air resistance reduces the maximum height achieved by the projectile. Therefore, Hmax decreases.

4. **Effect on Speed at Impact**:
- The speed at which the projectile strikes the ground can be analyzed using the components of velocity. The vertical component is affected by the maximum height and gravity.
- With air resistance, the vertical component of the velocity will be less than it would be without air resistance, leading to a decrease in the impact speed.

5. **Effect on Angle of Impact**:
- The angle at which the projectile strikes the ground can change due to the influence of air resistance. As the air resistance acts upward, it can alter the resultant velocity vector, potentially increasing the angle of impact.

6. **Conclusion**:
- After analyzing the effects of air resistance on range, maximum height, speed at impact, and angle of impact, we find that the only property that can show an increase is the angle of impact. This is because the air resistance can cause the projectile to strike the ground at a steeper angle compared to a situation without air resistance.

### Final Answer:
The property that shows an increase when air resistance is taken into account is the **angle of impact**.