Time taken by light to cross a distance of nuclear size is of the order of………. .

Answer

To find the time taken by light to cross a distance of nuclear size, we can follow these steps:

### Step 1: Understand the relationship between distance, speed, and time
We know from physics that the relationship between distance (d), speed (v), and time (t) is given by the formula:
\[ v = \frac{d}{t} \]
From this, we can rearrange the formula to find time:
\[ t = \frac{d}{v} \]

### Step 2: Determine the distance
The distance we are considering is the diameter of a nucleus. The typical diameter of a nucleus is approximately:
\[ d \approx 10^{-15} \text{ meters} \]

### Step 3: Determine the speed of light
The speed of light (v) in a vacuum is approximately:
\[ v \approx 3 \times 10^8 \text{ meters/second} \]

### Step 4: Substitute the values into the formula
Now we can substitute the values of distance and speed into the time formula:
\[ t = \frac{10^{-15}}{3 \times 10^8} \]

### Step 5: Simplify the expression
To simplify this, we can express it as:
\[ t = \frac{1}{3} \times 10^{-15} \times 10^{-8} \]
This simplifies to:
\[ t = \frac{1}{3} \times 10^{-23} \]

### Step 6: Calculate the numerical value
Calculating the numerical value gives us:
\[ t \approx 0.33 \times 10^{-23} \text{ seconds} \]

### Step 7: Express in scientific notation
We can express this in a more standard scientific notation:
\[ t \approx 3.3 \times 10^{-24} \text{ seconds} \]
However, since we are asked for the order of magnitude, we can round it to:
\[ t \approx 10^{-22} \text{ seconds} \]

### Final Answer
Thus, the time taken by light to cross a distance of nuclear size is of the order of:
\[ 10^{-22} \text{ seconds} \]

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