The Position Vector of a Particle Is R(t) $t = 1$

question 129

Multiple Choice

The position vector of a particle is r(t) . Find the requested vector.
-The acceleration at $t = 1$ for $\mathbf { r } ( \mathrm { t } ) = \mathrm { t } ^ { 5 } \mathbf { i } + 7 \ln \left( \frac { 1 } { 4 + \mathrm { t } } \right) \mathbf { j } + \frac { 3 } { \mathrm { t } } \mathbf { k }$

• A) \(\mathbf { a } ( 1 ) = 20 \mathbf { i } - 7 \mathbf { j } - 6 \mathbf { k }\)
• B) \(\mathbf { a } ( 1 ) = 20 \mathbf { i } + \frac { 7 } { 25 } \mathbf { j } + 6 \mathbf { k }\)
• C) \(\mathbf { a } ( 1 ) = 20 \mathbf { i } + \frac { 7 } { 25 } \mathbf { j } - 6 \mathbf { k }\)
• D) \(\mathbf { a } ( 1 ) = 20 \mathbf { i } + 7 \mathbf { j } + 6 \mathbf { k }\)

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