Let’s say you have a spring. You press on the spring with your finger. The spring goes down. This is the action force. Then, the spring goes back up after you take your finger off of it. This is known as the reaction force.
Answer:
<em><u>It can be a solid, liquid, gas</u></em><em><u>,</u></em><em><u>plasma</u></em><em><u>,</u></em><em><u>etc</u></em><em><u>. When waves travel through a medium, the particles of the medium are not carried along with </u></em><em><u>the</u></em><em><u> </u></em><em><u>wave</u></em><em><u>.</u></em><em><u>For example, water waves have to travel in water. Sound waves need a solid, a liquid or a gas to travel in.</u></em>
