Work done by 1kg of water when it falls through the height of 100m is

Options

A. 9.8J
B. 98J
C. 980J
D. 100J

Explanation

To find the work done by 1 kg of water when it falls through a height of 100 m, we can follow these steps:

### Step 1: Identify the formula for work done
The work done (W) can be calculated using the formula:
\[ W = F \cdot d \]
where:
- \( W \) is the work done,
- \( F \) is the force applied,
- \( d \) is the displacement (height fallen in this case).

### Step 2: Calculate the force acting on the water
The force acting on the water due to gravity can be calculated using the formula:
\[ F = m \cdot g \]
where:
- \( m \) is the mass of the water (1 kg),
- \( g \) is the acceleration due to gravity (approximately \( 9.8 \, \text{m/s}^2 \)).

Substituting the values:
\[ F = 1 \, \text{kg} \cdot 9.8 \, \text{m/s}^2 = 9.8 \, \text{N} \]

### Step 3: Determine the displacement
The displacement (height fallen) is given as:
\[ d = 100 \, \text{m} \]

### Step 4: Calculate the work done
Now, we can substitute the values of force and displacement into the work done formula:
\[ W = F \cdot d = 9.8 \, \text{N} \cdot 100 \, \text{m} \]

Calculating this gives:
\[ W = 980 \, \text{J} \]

### Final Answer
The work done by 1 kg of water when it falls through a height of 100 m is:
\[ \boxed{980 \, \text{J}} \]

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