When NASA was communicating with astronauts on the moon, the time from sending on the Earth to receiving on the moon was 1.28 s . Find the distance from Earth to the moon. (The speed of radio waves is \( 3.00^{\prime} 10^{8} \mathrm{~m} / \mathrm{s} \).) 1) 240000 km 2) 384000 km 3) 480000 km 4) 768000 km 5) 576.000 km

To determine the distance from Earth to the Moon based on the communication time, we'll use the relationship between distance, speed, and time: \[ \text{Distance} = \text{Speed} \times \text{Time} \] **Given:** - **Time (one-way):** 1.28 seconds - **Speed of radio waves (speed of light):** \( 3.00 \times 10^8 \) meters/second **Calculations:** 1. **Convert the speed to kilometers per second (km/s) for easier interpretation:** \[ 3.00 \times 10^8 \, \text{m/s} = 3.00 \times 10^5 \, \text{km/s} \] 2. **Calculate the distance:** \[ \text{Distance} = 3.00 \times 10^5 \, \text{km/s} \times 1.28 \, \text{s} = 3.84 \times 10^5 \, \text{km} \] \[ \text{Distance} = 384,000 \, \text{km} \] **Conclusion:** The distance from Earth to the Moon is **384,000 kilometers**. **Answer:** 384000 km