Mechanical (sound) waves are unable to travel through a vacuum, such as through space, but radio waves are transmitted to earth from satellites. how is this possible?
a) radio waves are electromagnetic waves.
b) satellites are located within our atmosphere.
c) radio waves are very high energy mechanical waves.
d) radio waves are changed to gamma rays for transmission.

The correct answer is option A

In a mechanical wave there is oscillation of the medium or matter. It is through the medium r matter that energy propagates. Sound waves require air for its propagation.

In Electromagnetic waves there are oscillation in the electric and magnetic fields which are perpendicular to each other and to the direction of propagation of the wave. Therefore, electromagnetic waves like radio waves can travel in vacuum.