Position Function and Velocity Function

Oct 13, 2025 by wbrum.org 4 views

Introduction

In this article, we will delve into the world of mathematical modeling and explore the motion of a particle along the x-axis. The position of the particle at any given time t is described by the function x(t) = 12e^(-t) sin(t). Our goal is to find the first time t at which the velocity of the particle changes. To achieve this, we will employ calculus techniques, specifically the derivative of the position function, to determine the velocity function. We will then analyze the velocity function to identify the first time t at which the velocity changes.

Position Function and Velocity Function

The position function x(t) = 12e^(-t) sin(t) describes the particle's position at time t. To find the velocity function, we need to take the derivative of the position function with respect to time t. Using the product rule and chain rule of differentiation, we can find the velocity function v(t).

Derivative of Position Function

To find the derivative of the position function x(t) = 12e^(-t) sin(t), we will apply the product rule and chain rule of differentiation.

v(t) = \frac{d}{dt} (12e^{-t} \sin t)
= 12 \frac{d}{dt} (e^{-t} \sin t)
= 12 \left( \frac{d}{dt} (e^{-t}) \sin t + e^{-t} \frac{d}{dt} (\sin t) \right)
= 12 \left( -e^{-t} \sin t + e^{-t} \cos t \right)
= 12e^{-t} (\cos t - \sin t)

Velocity Function

The velocity function v(t) = 12e^(-t) (cos(t) - sin(t)) describes the particle's velocity at time t. To find the first time t at which the velocity changes, we need to analyze the velocity function.

Critical Points of Velocity Function

To find the critical points of the velocity function, we need to find the values of t that make the velocity function equal to zero or undefined.

v(t) = 12e^{-t} (\cos t - \sin t) = 0
\Rightarrow \cos t - \sin t = 0
\Rightarrow \tan t = 1
\Rightarrow t = \frac{\pi}{4} + k \pi, k \in \mathbb{Z}

First Time of Velocity Change

The first time t at which the velocity changes is the first critical point of the velocity function. From the previous section, we found that the critical points of the velocity function are given by t = (π/4) + kπ, where k is an integer. Since we are interested in the first time t at which the velocity changes, we can set k = 0.

First Time of Velocity Change

The first time t at which the velocity changes is given by:

t = \frac{\pi}{4}

Conclusion

In this article, we explored the motion of a particle along the x-axis, described by the position function x(t) = 12e^(-t) sin(t). We found the velocity function v(t) by taking the derivative of the position function and analyzed the velocity function to identify the first time t at which the velocity changes. The first time t at which the velocity changes is given by t = π/4.

Future Work

In future work, we can explore other mathematical models of particle motion and apply calculus techniques to analyze their behavior. We can also investigate the physical implications of the velocity change and how it affects the particle's motion.

References

[1] Calculus, 3rd edition, Michael Spivak
[2] Differential Equations and Dynamical Systems, 3rd edition, Lawrence Perko

Glossary

Position function: A function that describes the particle's position at time t.
Velocity function: A function that describes the particle's velocity at time t.
Critical points: Values of t that make the velocity function equal to zero or undefined.
Calculus: A branch of mathematics that deals with the study of rates of change and accumulation.

Introduction

In our previous article, we explored the motion of a particle along the x-axis, described by the position function x(t) = 12e^(-t) sin(t). We found the velocity function v(t) by taking the derivative of the position function and analyzed the velocity function to identify the first time t at which the velocity changes. In this article, we will answer some frequently asked questions about the particle's motion.

Q&A

Q: What is the position function?

A: The position function x(t) = 12e^(-t) sin(t) describes the particle's position at time t.

Q: How do you find the velocity function?

A: To find the velocity function, we take the derivative of the position function with respect to time t. Using the product rule and chain rule of differentiation, we can find the velocity function v(t) = 12e^(-t) (cos(t) - sin(t)).

Q: What are the critical points of the velocity function?

A: The critical points of the velocity function are the values of t that make the velocity function equal to zero or undefined. We found that the critical points are given by t = (π/4) + kπ, where k is an integer.

Q: What is the first time t at which the velocity changes?

A: The first time t at which the velocity changes is the first critical point of the velocity function. We found that the first time t at which the velocity changes is given by t = π/4.

Q: What is the physical significance of the velocity change?

A: The velocity change represents a change in the particle's speed or direction. In this case, the velocity change occurs at time t = π/4.

Q: Can you provide more examples of position and velocity functions?

A: Yes, here are a few examples:

Position function: x(t) = 3t^2 + 2t - 5
Velocity function: v(t) = 6t + 2
Position function: x(t) = e^(-t) sin(t)
Velocity function: v(t) = e^(-t) (cos(t) - sin(t))

Q: How do you apply calculus to real-world problems?

A: Calculus is used to model and analyze real-world problems in physics, engineering, economics, and other fields. For example, calculus is used to model the motion of objects, the growth of populations, and the behavior of financial markets.

Q: What are some common applications of calculus?

A: Some common applications of calculus include:

Physics: Calculus is used to model the motion of objects, the behavior of electrical circuits, and the properties of materials.
Engineering: Calculus is used to design and optimize systems, such as bridges, buildings, and electronic circuits.
Economics: Calculus is used to model the behavior of economic systems, including the growth of populations and the behavior of financial markets.
Computer Science: Calculus is used to develop algorithms and models for computer graphics, machine learning, and data analysis.

Conclusion

In this article, we answered some frequently asked questions about the particle's motion. We hope that this article has provided a better understanding of the concepts and techniques used in calculus. If you have any further questions or topics you would like to discuss, please don't hesitate to ask.

References

[1] Calculus, 3rd edition, Michael Spivak
[2] Differential Equations and Dynamical Systems, 3rd edition, Lawrence Perko

Glossary

Position function: A function that describes the particle's position at time t.
Velocity function: A function that describes the particle's velocity at time t.
Critical points: Values of t that make the velocity function equal to zero or undefined.
Calculus: A branch of mathematics that deals with the study of rates of change and accumulation.