A ball is thrown upwards into air with a speed greater than its terminal speed. It lands at the same place from where it was thrown. Mark the correct statement (s).

Options

A. a. It acquires terminal speed before it gets to the highest point of the trajectory.
B. b. Before reaching the highest point of trajectory, its speed is continuously decreasing.
C. c. During the entire flight, the force of air resistance is greatest just after it is down
D. d. The magnitude of net force experienced by the ball is maximum just after it is thrown.

Explanation

To solve the problem, we need to analyze the motion of a ball thrown upwards with a speed greater than its terminal speed and determine which statements about its motion are correct.

### Step-by-Step Solution:

1. **Understanding Terminal Speed**:
- Terminal speed is the constant speed that a freely falling object eventually reaches when the resistance of the medium (air resistance) prevents further acceleration. When the ball is thrown upwards with a speed greater than its terminal speed, it will initially accelerate upwards.

2. **Forces Acting on the Ball**:
- When the ball is thrown upwards, two forces act on it:
- Gravitational force (mg) acting downwards.
- Air resistance (F_a) acting upwards, which is proportional to the velocity of the ball (F_a = k * v).
- Initially, the ball has a large upward velocity, so the air resistance is also large, but it is still less than the gravitational force.

3. **Motion Upwards**:
- As the ball moves upwards, its velocity decreases due to the net force acting downwards (mg + F_a). The speed of the ball continuously decreases until it reaches the highest point, where its velocity becomes zero.

4. **At the Highest Point**:
- At the highest point, the velocity of the ball is zero. Therefore, it cannot have acquired terminal speed before reaching this point because terminal speed is a constant speed that occurs when the forces are balanced (when the net force is zero).

5. **Motion Downwards**:
- After reaching the highest point, the ball starts descending. During this phase, the gravitational force (mg) acts downwards, and the air resistance (F_a) acts upwards. The ball will accelerate downwards until it reaches terminal speed, where the forces balance out.

6. **Analyzing the Statements**:
- **Statement A**: "It acquires terminal speed before it gets to the highest point of the trajectory."
- **Incorrect**: The ball cannot acquire terminal speed before reaching the highest point because at that point, its velocity is zero.

- **Statement B**: "Before reaching the highest point of the trajectory, its speed continuously decreases."
- **Correct**: The speed decreases as the ball moves upwards due to the net downward force.

- **Statement C**: "During the entire flight, the force of air resistance is greatest just after it is thrown."
- **Correct**: The air resistance is proportional to velocity, which is maximum just after the ball is thrown.

- **Statement D**: "The magnitude of the net force experienced by the ball is maximum just after it is thrown."
- **Correct**: The net force is maximum just after the throw because the gravitational force is at its maximum and the air resistance is also significant at that moment.

### Conclusion:
The correct statements are:
- Statement B
- Statement C
- Statement D