The moon is `4xx10^(8)m` from the earth. A radar signal transmitted from the earth will reach the moon in about

Options

A. 5.2 s
B. 1.3 s
C. 2.6 s
D. 0.70 s

Answer

To solve the problem of how long it takes for a radar signal to travel from Earth to the Moon, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Data**:
- Distance from Earth to the Moon, \( d = 4 \times 10^8 \) meters.
- Speed of radar signal (which is the speed of light), \( c = 3 \times 10^8 \) meters per second.

2. **Use the Formula for Time**:
- The formula to calculate time \( t \) when distance and speed are known is:
\[ t = \frac{d}{c} \]

3. **Substitute the Values**:
- Substitute the values of distance and speed into the formula:
\[ t = \frac{4 \times 10^8 \text{ m}}{3 \times 10^8 \text{ m/s}} \]

4. **Perform the Calculation**:
- Simplifying the fraction:
\[ t = \frac{4}{3} \text{ seconds} \]
- This can be calculated as:
\[ t \approx 1.33 \text{ seconds} \]

5. **Conclusion**:
- The radar signal transmitted from Earth will reach the Moon in approximately **1.33 seconds**.