The unit of "impulse per unit area" is same as that of

Options

A. Viscosity
B. Surface tension
C. Bulk modulus
D. Force

Answer

To solve the problem of determining what unit "impulse per unit area" corresponds to, we can follow these steps:

### Step 1: Understand Impulse
Impulse is defined as the change in momentum. Mathematically, it can be expressed as:
\[ \text{Impulse} = \Delta p = \int F \, dt \]
where \( F \) is the force applied over a time interval.

### Step 2: Determine the Unit of Impulse
The unit of impulse can be derived from the unit of momentum. Momentum (\( p \)) is given by:
\[ p = mv \]
where \( m \) is mass and \( v \) is velocity. Therefore, the unit of momentum is:
\[ \text{Unit of momentum} = \text{kg} \cdot \text{m/s} \]
Thus, the unit of impulse, which is the same as the unit of momentum, is:
\[ \text{Unit of impulse} = \text{kg} \cdot \text{m/s} \]

### Step 3: Calculate Impulse per Unit Area
Now, we need to find the unit of "impulse per unit area." This can be expressed as:
\[ \text{Impulse per unit area} = \frac{\text{Impulse}}{\text{Area}} \]
The unit of area is \( \text{m}^2 \). Therefore, the unit of impulse per unit area becomes:
\[ \text{Unit of impulse per unit area} = \frac{\text{kg} \cdot \text{m/s}}{\text{m}^2} = \text{kg} \cdot \frac{1}{\text{m} \cdot \text{s}} \]

### Step 4: Identify Corresponding Physical Quantity
The derived unit \( \text{kg} \cdot \text{m}^{-1} \cdot \text{s}^{-1} \) corresponds to the unit of viscosity. Viscosity is defined as the measure of a fluid's resistance to deformation or flow, and its unit in the SI system is \( \text{Pa} \cdot \text{s} \) or \( \text{kg} \cdot \text{m}^{-1} \cdot \text{s}^{-1} \).

### Conclusion
Thus, the unit of "impulse per unit area" is the same as that of viscosity.