When astronauts are on spacewalks outside of the International Space Station, they must use a communication system with radio waves to be able to talk to each other. Explain why focusing on the difference between sound and light waves

Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum.

They make use of radio waves. Radio waves signal are sent their headsets that in turn translates the signal in the form of sound. While communicating with people on Earth – the radio waves are transmitted which in turn are transformed to sound wave by a radio set. Radio waves comes from the light spectrum called Electromagnetic Spectrum and thus they are light waves. Unlike sound, light waves doesn’t need a medium to travel and it is for this reason that the sun ray travels through space to the Earth

We all know who was the first man that landed on moon? But were the first words ever heard in space?

It was the announcement of landing that was said by Neil Armstrong: “Lunar Module has landed on moon”

Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum.

Explanation:

d. air pressure decreases as altitude increases.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.