The pressure exerted by an electromagnetic wave of intensity l `("watt/m"^(2))` on a nonreflecting surface is [c is the velocity of light]

Options

A. lc
B. `lc^(2)`
C. `l//c`
D. `l//c^(2)`

Explanation

To solve the problem of finding the pressure exerted by an electromagnetic wave of intensity \( I \) on a non-reflecting surface, we can follow these steps:

### Step 1: Understand the relationship between intensity, energy, and pressure
The intensity \( I \) of an electromagnetic wave is defined as the power per unit area. Mathematically, it can be expressed as:
\[ I = \frac{P}{A} \]
where \( P \) is the power and \( A \) is the area.

### Step 2: Relate intensity to energy and force
The intensity can also be defined as the energy passing through a unit area per unit time. Thus, we can express it as:
\[ I = \frac{E}{A \cdot t} \]
where \( E \) is the energy, \( A \) is the area, and \( t \) is the time.

### Step 3: Relate force to pressure
The pressure \( P \) exerted by the wave can be defined as the force \( F \) per unit area \( A \):
\[ P = \frac{F}{A} \]
From the definition of intensity, we can express the force in terms of intensity and area.

### Step 4: Express energy in terms of force and distance
We know that energy can also be expressed as:
\[ E = F \cdot d \]
where \( d \) is the distance over which the force is applied.

### Step 5: Relate distance and time to velocity
The distance \( d \) can be related to time \( t \) and velocity \( v \) (in this case, the speed of light \( c \)):
\[ d = c \cdot t \]
Substituting this into the energy equation gives:
\[ E = F \cdot (c \cdot t) \]

### Step 6: Substitute into the intensity equation
Now substituting \( E \) back into the intensity equation:
\[ I = \frac{F \cdot (c \cdot t)}{A \cdot t} \]
This simplifies to:
\[ I = \frac{F \cdot c}{A} \]

### Step 7: Solve for pressure
Rearranging the equation to solve for pressure \( P \):
\[ F = P \cdot A \implies I = \frac{P \cdot c}{A} \]
Thus, we can express pressure as:
\[ P = \frac{I}{c} \]

### Conclusion
The pressure exerted by an electromagnetic wave of intensity \( I \) on a non-reflecting surface is given by:
\[ P = \frac{I}{c} \]