Select all that apply.
there is no sound in the vacuum of space. why?
sound must travel through something that vibrates.
there is no energy in space.
there is no air to vibrate the human eardrum.
space is too full of light energy.

Sound must travel through something that vibrates.

There is no air to vibrate the human eardrum.

Explanation:

Waves can be divided into two types:

- Electromagnetic waves: these are waves produced by the oscillations of electric and magnetic field. This type of wave does not need a medium to propagate, so they can also travel through a vacuum

- Mechanical waves: these are waves produced by the vibrations of the particles in a medium - therefore, they do need a medium to propagate. Sound waves are part of this type, so they cannot travel through a vacuum.

According to these definitions, we can say that the correct choices are the following:

Sound must travel through something that vibrates. --> because they are mechanical waves

There is no air to vibrate the human eardrum. --> because they are mechanical waves

co2reflects heat radiation back to earth buning coal and oil emits co2 globe warms

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y