If mars is located an average of 228 million km from earth, and radio waves travel at 300,000 km/s, how many minutes does it take a communication to reach earth from mars ?

It depends

Explanation:

Earth and Mars are constantly moving and rotating around the sun, as such the distance between them changes dramatically throughout the year. At their closest points signals only take a little more than 4 minutes to travel between the two planets, but it can sometimes take as long as twenty minutes.

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .