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 regarding the projectile motion and the speed of the projectile at the top of its path, we can break it down into the following steps:

### Step 1: Understand the motion of the projectile
A projectile fired from the ground follows a parabolic path due to the influence of gravity. The motion can be analyzed in two dimensions: horizontal (x-direction) and vertical (y-direction).

**Hint:** Remember that projectile motion can be separated into horizontal and vertical components.

### Step 2: Identify the components of velocity
When a projectile is launched at an angle θ with an initial speed u, its initial velocity can be resolved into two components:
- Horizontal component: \( u_x = u \cos \theta \)
- Vertical component: \( u_y = u \sin \theta \)

**Hint:** Use trigonometric functions to resolve the initial velocity into its components.

### Step 3: Analyze the horizontal motion
The horizontal component of the velocity \( u_x \) remains constant throughout the projectile's flight because there is no horizontal acceleration (ignoring air resistance).

**Hint:** Horizontal motion in projectile motion is uniform due to the absence of horizontal forces.

### Step 4: Analyze the vertical motion
The vertical component of the velocity \( u_y \) changes due to the acceleration caused by gravity (g). As the projectile rises, the vertical component decreases until it reaches the highest point.

**Hint:** Remember that the vertical velocity decreases until it becomes zero at the peak of the trajectory.

### Step 5: Determine the speed at the highest point
At the highest point of the projectile's path:
- The vertical component of the velocity \( u_y \) becomes zero.
- The only component of velocity remaining is the horizontal component \( u_x \).

Thus, at the top of the path, the speed of the projectile is at its minimum, equal to the horizontal component \( u_x \).

**Hint:** At the peak of the trajectory, the vertical velocity is zero, leaving only the horizontal component.

### Step 6: Conclusion
The speed of the projectile is minimum at the top of its path because, at that point, it only has the horizontal component of velocity, while the vertical component is zero.

**Final Answer:** The speed of the projectile is minimum at the top of its path because it only has the horizontal component of velocity, which remains constant, while the vertical component becomes zero.