Final answer:
You would not hear a clap on the moon without a spacesuit, as there is no atmosphere to carry the sound. The best communication method without a radio is flashing a light. Astronauts can't hear an explosion on the moon from orbit because there's no atmosphere for sound to travel through.
Step-by-step explanation:
If you are on the moon without a spacesuit and clap your hands, you would not be able to hear the sound of the clap. This is because the moon has no atmosphere to carry sound waves to your ears. Sound requires a medium like air, water, or a solid to travel through, and in the vacuum of space, there is no medium for the sound waves to propagate.
The best way to communicate with another astronaut on the moon if your radio breaks would be by flashing a light, because light can travel through the vacuum of space. Yelling would not work because there is no air on the moon to carry your voice.
Astronauts orbiting the moon would not be able to hear an explosion on the surface for the same reason: there is no atmosphere to carry the sound. It has nothing to do with the speed at which sound travels or the speed of the spaceship.
In space, sound cannot travel because it requires a medium, such as air or water, to propagate. The moon does not have an atmosphere, so there is no air to transmit sound waves. Therefore, you would not be able to hear your hands clapping even if you were on the moon without wearing a spacesuit.