Sec. 5-2 Tension and normal forces (张力与压力 )Tension force(such as in a stretched rope or string), arises because each small element of the string pulls on the element next to it If the mass of the rope is negligible, the values of the force exerted on the two ends of the rope must be nearly equal to each otherSec. 5-2 Tension and normal forces (张力与压力) (1) Tension force (such as in a stretched rope or string), arises because each small element of the string pulls on the element next to it. m If the mass of the rope is negligible, the values of the force exerted on the two ends of the rope must be nearly equal to each other