Final answer:
In a tug-of-war, students' muscles must tighten and contract to pull on the rope, creating tension that is countered by the opposing team's force. These muscle actions are the same as those used in arm-wrestling, another sport dependent on muscle contractions against an opposing force.
Step-by-step explanation:
The correct answer to the student's question is c. tighten and contract. In a scenario like a tug-of-war, students' muscles must perform these actions to pull the rope effectively. During the tug-of-war, muscles undergo isometric contractions, where the muscles are activated but do not significantly change length. In this case, the muscle fibers tighten, which is the initial engagement and stiffening of the muscles, and then they contract, where the muscle fibers actively generate force against resistance in an attempt to shorten. This contraction opposes the counterforce exerted by the opposing team.
It is essential to understand that tension in ropes during tug-of-war represents the force that the participants must overcome. The tension in the rope is a result of the force applied by both teams. In the case of arm-wrestling, which relies heavily on muscle contractions, the same principle applies. The repeated actions of tightening and contracting are crucial for both maintaining one's position against the opponent's force and for attempting to overcome the opponent's resistance in both sports.