A Particle Moves with Position Function $\mathbf { r } ( t ) = \left( 21 t - 7 t ^ { 3 } - 6 \right) \mathbf { i } + 21 t ^ { 2 } \mathbf { j }$

question 8

Multiple Choice

A particle moves with position function $\mathbf { r } ( t ) = \left( 21 t - 7 t ^ { 3 } - 6 \right) \mathbf { i } + 21 t ^ { 2 } \mathbf { j }$
Find the tangential component of the acceleration vector. Select the correct answer.

• A) \(a _ { T } = 6 t\)
• B) \(a _ { T } = 42 t\)
• C) \(a _ { T } = 42 t + 6\)
• D) \(a _ { T } = 642 t\)
• E) \(a _ { T } = - 66 t\)

---

Definitions:

Genetic Plan

The predetermined genetic information carried by an organism that dictates its developmental processes and inherited traits.

Motor Development

The progression of muscle coordination and movement abilities in individuals, especially during the early years of life.

Gesell

Refers to Arnold Gesell, an American psychologist and pediatrician known for his work in child development.

Maturation

The process of becoming mature, encompassing growth and development in physical, intellectual, or emotional capabilities.