<em>B. Sound waves can move through various mediums.</em>
<h3><u>Explanation;</u></h3>
<em><u>A wave is a transmission of a disturbance from one point to another</u></em>. It involves transmission of energy from the source to another point.
<u><em>A wave may or may not require a medium for transmission.</em></u> Waves that require medium for transmission are called <em><u>mechanical waves </u></em>and those that do not require medium for transmission are known as <em><u>electromagnetic waves</u></em>.
<em><u>Light is an example of electromagnetic wave therefore it can be blocked when obstacles are placed on its path.</u></em> However, for the case of sound waves, they can not be blocked by an obstacle as sound would travel through the medium used to block.
Without this slack, a locomotive might simply sit still and spin its wheels. The loose coupling enables a longer time for the entire train to gain momentum, requiring less force of the locomotive wheels against the track. In this way, the overall required impulse is broken into a series of smaller impulses. (This loose coupling can be very important for braking as well).
