A rocket works on the principle of conservation of

Options

A. mass
B. angular momentum
C. energy
D. linear momentum

Answer

To solve the question regarding the principle on which a rocket operates, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Rocket Motion**:
A rocket moves in one direction, and to propel itself, it ejects fuel in the opposite direction. This is a fundamental aspect of how rockets operate.

2. **Identifying the Forces**:
When the rocket ejects fuel, it experiences a reaction force that propels it forward. This is in accordance with Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

3. **Applying Conservation Principles**:
We need to determine which conservation principle applies here. The options given are conservation of mass, angular momentum, energy, or linear momentum.

4. **Analyzing Momentum**:
- The momentum of the rocket before the fuel is ejected must equal the momentum of the rocket and the ejected fuel after the fuel is ejected (assuming no external forces act on the system).
- If we denote the mass of the rocket as \( m_r \), the mass of the fuel as \( m_f \), the velocity of the rocket as \( v_r \), and the velocity of the ejected fuel as \( v_f \), we can express this as:
\[ m_r v_r + m_f v_f = 0 \]
- This shows that the momentum of the rocket is balanced by the momentum of the ejected fuel.

5. **Conclusion**:
Since the rocket's motion relies on the conservation of momentum, specifically linear momentum, we conclude that the rocket works on the principle of conservation of linear momentum.

### Final Answer:
The rocket works on the principle of conservation of **linear momentum**.

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