The Position Vector of a Particle Is R(t) $t = 0$

question 135

Multiple Choice

The position vector of a particle is r(t) . Find the requested vector.
-The velocity at $t = 0$ for $\mathbf { r } ( t ) = \cos ( 5 t ) \mathbf { i } + 7 \ln ( t - 2 ) \mathbf { j } - \frac { t ^ { 3 } } { 10 } \mathbf { k }$

• A) \(\mathbf { v } ( 0 ) = - 5 i - \frac { 7 } { 2 } \mathbf { j }\)
• B) \(v ( 0 ) = 5 i - \frac { 7 } { 2 } j\)
• C) \(\mathbf { v } ( 0 ) = - \frac { 7 } { 2 } \mathrm { j }\)
• D) \(\mathbf { v } ( 0 ) = \frac { 7 } { 2 } \mathbf { j }\)

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