Let $\mathbf { a } ( t ) = - 9.5 \mathbf { k }$

Multiple Choice

Let $\mathbf { a } ( t ) = - 9.5 \mathbf { k }$ be the acceleration of an object with velocity $\mathbf { v } ( t )$ . If $\mathbf { v } ( 0 ) = \mathbf { i } + 2 \mathbf { j }$ then the speed $\| \mathbf { v } ( t ) \|$ is

A) $\sqrt { 9.5 t ^ { 2 } + 5 }$
B) $\sqrt { 90.25 t ^ { 2 } - 25 }$
C) $\sqrt { 90.25 t ^ { 2 } + 25 }$
D) $\sqrt { 90.25 t ^ { 2 } + 5 }$
E) $\sqrt { 90.25 t ^ { 2 } - 5 }$