A car, while moving, is facing a wind from the opposite direction. The work done by the wind on the car will be ______.

Options

A. Infinity
B. Positive
C. Zero
D. Negative

Answer

To solve the question regarding the work done by the wind on a car that is moving against it, we can follow these steps:

### Step 1: Understand the Concept of Work
Work is defined as the product of force and displacement in the direction of the force. Mathematically, it is expressed as:
\[ \text{Work} = \text{Force} \times \text{Displacement} \times \cos(\theta) \]
where \( \theta \) is the angle between the force and the direction of displacement.

**Hint:** Remember that the angle \( \theta \) plays a crucial role in determining whether the work is positive, negative, or zero.

### Step 2: Analyze the Situation
In this scenario, the car is moving in one direction while the wind is blowing in the opposite direction. This means that the force exerted by the wind is opposite to the direction of the car's displacement.

**Hint:** Identify the direction of the force (wind) and the direction of displacement (car's movement) to determine the angle \( \theta \).

### Step 3: Determine the Angle \( \theta \)
Since the wind is opposing the motion of the car, the angle \( \theta \) between the force of the wind and the displacement of the car is 180 degrees.

**Hint:** Recall that \( \cos(180^\circ) = -1 \).

### Step 4: Calculate the Work Done
Using the work formula:
\[ \text{Work} = \text{Force} \times \text{Displacement} \times \cos(180^\circ) \]
Since \( \cos(180^\circ) = -1 \), we can conclude that:
\[ \text{Work} = \text{Force} \times \text{Displacement} \times (-1) \]
This indicates that the work done by the wind on the car is negative.

**Hint:** Negative work indicates that the force is acting in the opposite direction to the displacement.

### Step 5: Conclusion
Therefore, the work done by the wind on the car will be negative.

**Final Answer:** The work done by the wind on the car will be negative.