To hit a overhand, you jump and smack the ball with your palm when the ball goes over the net
To hit a underhand, you put the ball on the undominant hand and you throw it up then you smack it with your palm
the advantages of a underhand is it might not work and may hit the net
advantage of a overhand is, it goes fast and the opponent might not see it coming.
A mechanical wave is created when a medium allows the transfer of energy, or moves back and forth or up and down. It <span> is a </span>wave that is a vibration in matter, transferring energy through a material. <span>While </span>waves<span> can move over long distances, the movement of the medium of transmission is limited. Hope this answers the question.</span>
Chronic stress<span>, or a constant </span>stress<span> experienced over a prolonged period of time, can contribute to long-term problems for </span>heart<span> and blood vessels. The consistent and ongoing increase in </span>heart<span> rate, and the elevated levels of </span>stress<span> hormones and of blood pressure, can take a toll on the body</span>
