Table 4.

Differences among dependent variables, surface area (AREA), static (μ_S) and kinetic (μ_K) friction coefficients, and the difference between them (μ_S – μ_K) for used ropes^{^z}.

Dependent variable	Ring	APu	SBHVu	BSu	TBu
Area (cm²)	N/A	34.13 (1.277)*	30.19 (0.477)*	30.97 (1.142)*	32.06 (0.548)*
μ_S	AL	0.32 (0.004)*a	0.27 (0.004)a
μ_S	PAL	0.31 (0.004)*a	0.25 (0.004)*a
μ_S	STEEL	0.34 (0.003)*b	0.28 (0.011)*a
μ_K	AL	0.31 (0.003)*a	0.26 (0.003)*a
μ_K	PAL	0.31 (0.003)*a	0.25 (0.003)*a
μ_K	STEEL	0.33 (0.002)*b	0.28 (0.009)*a
μ_S – μ_K	AL	0.01 (0.002)*a†	0.01 (0.002)*a†
μ_S – μ_K	PAL	0.01 (0.002)*a†	0.00 (0.002)*a
μ_S – μ_K	STEEL	0.01 (0.001)*a†	0.01 (0.007)*a

↵^zMeans (standard errors are in parentheses) are followed by up to three symbols. The asterisk indicates that the mean for the rope and ring combination is different than the same rope in new condition (P < 0.0001). Means for new ropes are presented in Table 2. Different letters following means of a dependent variable within a rope indicate differences among rings (P < 0.01) for that dependent variable. Differences between static and kinetic friction coefficients (P < 0.01) for each rope and ring combination are indicated by a dagger. BSu and TBu refer to used Blue Streak and Tru-Blue ropes, respectively.
N/A = not applicable.