Problem 11E

Artifical joints consist of a ceramic ball mounted on a taper.The article “Friction in Orthopaedic Zirconia Taper Assemblies”(W.Macdonald,A.Aspenberg,et al.,proceedings of the Institution of Mechanical Engineers,2000:685-692)present data on the coefficient of friction for a push-on load of 2kN for taper assemblies made from two zirconium alloys and employing three different neck lengths.Five measurements were made for each combination of material and neck length.The result presented in the following table are consistent with the cell means and standard deviation presented in the article.

Taper Material |
Neck Length |
Coefficient of friction |
||||

CPTi-ZrO2 |
Short |
0.254 |
0.195 |
0.281 |
0.289 |
0.220 |

CPTi-ZrO2 |
Medium |
0.196 |
0.220 |
0.185 |
0.259 |
0.197 |

CPTi-ZrO2 |
Long |
0.329 |
0.481 |
0.320 |
0.296 |
0.178 |

TiAlloy-ZrO2 |
Short |
0.150 |
0.118 |
0.158 |
0.175 |
0.131 |

TiAlloy-ZrO2 |
Medium |
0.180 |
0.184 |
0.154 |
0.156 |
0.177 |

TiAlloy-ZrO2 |
Long |
0.178 |
0.198 |
0.201 |
0.199 |
0.210 |

a.Compute the main effect and interaction.

b. Construct an ANOVA table. You may give ranges for the P-values.

c. Is the additive model plausible? Provide the value of a test statistic ,its null distribution and the P-value.

d. Can the effect of material on the coefficient of frictionbe described by interpreting the main effects of material? If so, interpret the main effects. If not, explain why not.

e. Can the effect of neck length on the coefficient of friction be described by interpreting the main effects of neck length? If so, interpret the main effects, using multiple comparisons at the 5% level if necessary. If not, explain why not.

SMAD 150 Notes 9/14 Media Effects (Potter, Chapters 14, 13, and Appendix B) Key Ideas: ● Media effects are constantly occurring ● Media work with other factors ● You can control the effects process ● When we take a fourdimensional perspective (timing, type, valence, intentionality), we can better appreciate the broad range of media effects More to do with...