Force applied to open or close a water tap is an example of _____________.

Options

A. elastic collision
B. conservation of momentum
C. couple
D. application of Newton's law of motion

Answer

To solve the question "Force applied to open or close a water tap is an example of _____________", we can follow these steps:

### Step 1: Understand the Mechanism of the Water Tap
To open or close a water tap, we need to apply a force to its lever. This force is necessary to initiate the movement of the tap.

**Hint:** Think about how a lever works and what kind of motion is involved when you turn a tap.

### Step 2: Identify the Type of Motion Involved
When we apply force to the lever of the tap, we are not just pushing it straight up or down; instead, we are rotating it around a pivot point. This means that we are applying a torque or moment to the lever.

**Hint:** Consider what happens to the lever when you apply force at a distance from the pivot point.

### Step 3: Define Torque or Moment
Torque (or moment) is defined as the rotational effect of a force applied at a distance from the pivot point. In the case of the water tap, the force we apply creates a rotational motion, which is essential for opening or closing the tap.

**Hint:** Recall the formula for torque: Torque = Force × Distance from pivot.

### Step 4: Recognize the Type of Force Applied
When we apply force to the lever, we often do so in a manner that involves two equal and opposite forces acting on the lever. This is known as a couple. A couple consists of two equal forces acting in opposite directions, creating a rotational effect.

**Hint:** Think about how you would use both hands to turn the tap, applying force in opposite directions.

### Step 5: Conclude the Answer
Given that the force applied to open or close a water tap involves creating a rotational effect through a couple, we can conclude that the force applied to open or close a water tap is an example of a **couple moment**.

**Final Answer:** The force applied to open or close a water tap is an example of **a couple moment**.