Which statement is true about the strength of knots?

The statement regarding knots and their strength is accurate when it mentions that a knot with a small internal radius can weaken the rope. This is because when a knot is tied, it creates bends and twists in the rope, especially at points where the rope contacts itself or bends sharply. The tighter and sharper the bend (which corresponds to a smaller internal radius), the higher the stress concentration on the rope fibers at that point. This stress can lead to a significant reduction in the overall strength of the rope, as some of the rope fibers may be forced to bear more load than they are designed to handle, increasing the risk of failure or breakage.

When considering true statements about the strength of knots, it's also important to note that different knots are designed for specific uses and can have varying effects on rope strength depending on their construction and the materials used. Some knots will indeed lessen the rope's strength more than others, particularly under certain conditions such as heavy loads or when the rope is subject to dynamic forces. This highlights the significance of understanding knot characteristics and their implications for safety in rope rescue operations.