$\text { Find the velocity vector in terms of } u _ { r } \text { and } u _ { \theta } \text {. }$

question 73

Multiple Choice

$\text { Find the velocity vector in terms of } u _ { r } \text { and } u _ { \theta } \text {. }$
- $r = 2 \cos 2 t$ and $\theta = 4 t$

• A) \(\mathbf { v } = ( - 8 \sin 4 \mathrm { t } ) \mathbf { u } _ { \mathrm { r } } + 4 \cos 4 \mathrm { tu } _ { \theta }\)
• B) \(\mathbf { v } = ( 4 \sin 2 \mathrm { t } ) \mathbf { u } _ { \mathrm { r } } + 8 \cos 2 \mathrm { tu } _ { \theta }\)
• C) \(\mathbf { v } = ( - 4 \sin 2 \mathrm { t } ) \mathrm { u } _ { \mathrm { r } } + 8 \cos 2 \mathrm { tu } _ { \theta }\)
• D) \(v = ( - 2 \sin 2 t ) u _ { r } + 8 \cos 2 t u _ { \theta }\)

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Chi-squared Test

A statistical test used to determine whether there is a significant association between categorical variables.

Two-tailed Test

A statistical test in which the critical area of a distribution is two-sided and tests whether a sample is either greater than or less than a certain range of values.

Chi-squared Goodness-of-fit

A statistical test used to determine if a sample data fits a distribution from a certain population, based on the differences between observed and expected frequencies.

Two-tail Test

A statistical test that considers the possibility of observing extreme outcomes in both tails of the distribution.