A projectile fired from the ground follows a parabolic path. The speed of the projectile is minimum at the top of its path.

Explanation

To solve the question of why the speed of a projectile is minimum at the top of its parabolic path, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Projectile Motion**:
- A projectile is an object that is thrown into the air with an initial velocity and follows a curved path under the influence of gravity. This path is a parabola.

**Hint**: Remember that projectile motion can be analyzed in two dimensions: horizontal (x-direction) and vertical (y-direction).

2. **Components of Velocity**:
- The velocity of the projectile can be broken down into two components: the horizontal component (Vx) and the vertical component (Vy).
- Vx remains constant throughout the motion because there are no horizontal forces acting on the projectile (assuming air resistance is negligible).
- Vy changes due to the acceleration caused by gravity.

**Hint**: Think about how gravity affects the vertical motion of the projectile.

3. **Behavior at Maximum Height**:
- At the maximum height of the projectile's path, the vertical component of the velocity (Vy) becomes zero. This is because the projectile stops rising and is about to start falling.
- At this point, the only component of velocity that remains is the horizontal component (Vx).

**Hint**: Visualize the trajectory of the projectile and where it reaches its peak.

4. **Calculating Speed at the Top**:
- The speed of the projectile at any point in its trajectory can be calculated using the Pythagorean theorem:
\[ \text{Speed} = \sqrt{Vx^2 + Vy^2} \]
- At the maximum height, since Vy = 0, the speed simplifies to:
\[ \text{Speed at maximum height} = Vx \]

**Hint**: Recall that speed is the magnitude of velocity, which combines both components.

5. **Comparison of Speeds**:
- At points other than the maximum height, both Vx and Vy contribute to the overall speed, making it greater than Vx alone.
- Therefore, the speed at the maximum height is the minimum speed of the projectile during its flight.

**Hint**: Consider how the vertical motion affects the overall speed at different points in the trajectory.

### Conclusion:
The speed of the projectile is minimum at the top of its path because, at that point, the vertical component of the velocity is zero, leaving only the horizontal component. Thus, the overall speed is simply equal to the horizontal component, which is less than the speed at any other point in the trajectory where both components are present.