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) \(a _ { T } = - 66 t\)

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Definitions:

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Attractive forces between unlike substances, such as water molecules adhering to glass surfaces.

Cohesive Forces

The attractive forces between like molecules that are responsible for the tendency of certain materials to stick together.

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The process by which DNA is duplicated; ordinarily a semiconservative process in which a double helix gives rise to two double helices, each with an "old" strand and a newly synthesized strand.

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Atoms of the same element that have different numbers of neutrons in their nuclei, causing them to be unstable and decay, releasing radiation.