Torque is

Options

A. the rate of change of linear momentum.
B. the rate of change of angular momentum
C. angular impulse x time
D. angular impulse x distance

Answer

To understand what torque is, we can break it down step by step:

### Step 1: Definition of Torque
Torque is a measure of the rotational force applied to an object. It determines how effectively a force can cause an object to rotate about an axis.

### Step 2: Relation to Angular Momentum
Torque is related to angular momentum. Just as force is the rate of change of linear momentum, torque is the rate of change of angular momentum.

### Step 3: Mathematical Expression
The mathematical expression for torque (τ) can be given as:
\[ \tau = I \cdot \alpha \]
where:
- \( I \) is the moment of inertia of the object,
- \( \alpha \) is the angular acceleration.

### Step 4: Rate of Change of Angular Momentum
From the definition of torque, we can also express it as:
\[ \tau = \frac{dL}{dt} \]
where \( L \) is the angular momentum. This shows that torque is the rate of change of angular momentum with respect to time.

### Step 5: Conclusion
Thus, the correct answer to the question "What is torque?" is that it is the rate of change of angular momentum.

### Final Answer
The correct option is: **2. Rate of change of angular momentum.**

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