Question

Two astronauts are floating close to each other in space. Can they talk to each other without using any special device? Give reasons.

• A. yes, in space there is enough air for travelling sound.
• B. no, there is a vacuum in space.
• C. yes, no gravity in space
• D. none of these

Answer 1

The correct option is B no, there is a vacuum in space.

Astronauts float around in space because there is no gravity in space. Everyone knows that the farther you get from Earth, the less the gravitational force is. Astronauts are so far from the Earth that gravity is so small. There is no atmosphere in space, therefore propagation of sound is not possible there. Sound needs a material medium for their propagation. In the space, there is no material medium so astronauts cannot listen to each other.
Hence, to do conversation on space the astronauts uses an instrument which can transmit and detect electromagnetic waves.