Power rule of differentiation

Oct 13, 2025 by wbrum.org 117 views

Introduction

In physics, the position of an object is often described by a mathematical function, known as the position function. This function gives the position of the object at any given time. In this article, we will explore the relationship between the position function and the velocity function of a particle. We will use the position function $s(t)=3 t^3+4 t+9$ to find the velocity at time $t$ and at a specific time $t=3$ seconds.

Position Function

The position function $s(t)=3 t^3+4 t+9$ describes the position of the particle at time $t$ . This function is a polynomial of degree 3, which means it has three terms: a cubic term, a linear term, and a constant term.

Velocity Function

The velocity function $v(t)$ is the derivative of the position function $s(t)$ . In other words, it gives the rate of change of the position with respect to time. To find the velocity function, we need to differentiate the position function with respect to time.

Finding the Velocity Function

To find the velocity function, we will use the power rule of differentiation, which states that if $f(x)=x^n$ , then $f'(x)=nx^{n-1}$ . We will apply this rule to each term of the position function.

For the cubic term $3t^3$ , we have $3(3)t^{3-1}=9t^2$ .
For the linear term $4t$ , we have $4(1)t^{1-1}=4$ .
For the constant term $9$ , we have $0$ since the derivative of a constant is always $0$ .

Therefore, the velocity function is given by:

$v(t)=\frac{ds}{dt}=9t^2+4$

Finding the Velocity at Time $t=3$ Seconds

To find the velocity at time $t=3$ seconds, we need to substitute $t=3$ into the velocity function.

$v(3)=9(3)^2+4=9(9)+4=81+4=85$

Therefore, the velocity at time $t=3$ seconds is $85 \frac{m}{s}$ .

Discussion

In this article, we have seen how to find the velocity function of a particle given its position function. We have used the power rule of differentiation to find the velocity function and have applied it to a specific position function. We have also seen how to find the velocity at a specific time by substituting the time into the velocity function.

The velocity function is an important concept in physics, as it describes the rate of change of the position of an object with respect to time. It is used to describe the motion of objects in various fields, such as mechanics, electromagnetism, and quantum mechanics.

Conclusion

In conclusion, we have seen how to find the velocity function of a particle given its position function. We have used the power rule of differentiation to find the velocity function and have applied it to a specific position function. We have also seen how to find the velocity at a specific time by substituting the time into the velocity function.

References

[1] Halliday, D., Resnick, R., & Walker, J. (2013). Fundamentals of Physics. John Wiley & Sons.
[2] Serway, R. A., & Jewett, J. W. (2018). Physics for Scientists and Engineers. Cengage Learning.

Mathematical Formulas

Power rule of differentiation: if $f(x)=x^n$ , then $f'(x)=nx^{n-1}$ .
Velocity function: $v(t)=\frac{ds}{dt}$ .
Position function: $s(t)=3 t^3+4 t+9$ .

Glossary

Velocity: the rate of change of the position of an object with respect to time.
Position function: a mathematical function that describes the position of an object at any given time.
Power rule of differentiation: a rule used to find the derivative of a polynomial function.
Velocity and Position: A Q&A Guide =====================================

Introduction

In our previous article, we explored the relationship between the position function and the velocity function of a particle. We used the position function $s(t)=3 t^3+4 t+9$ to find the velocity at time $t$ and at a specific time $t=3$ seconds. In this article, we will answer some frequently asked questions about velocity and position.

Q&A

Q: What is the difference between velocity and speed?

A: Velocity and speed are related but distinct concepts. Speed is a scalar quantity that describes how fast an object is moving, while velocity is a vector quantity that describes not only how fast an object is moving but also its direction.

Q: How do you find the velocity of an object?

A: To find the velocity of an object, you need to find the derivative of its position function with respect to time. This is because velocity is the rate of change of position with respect to time.

Q: What is the unit of velocity?

A: The unit of velocity is typically measured in meters per second (m/s) or kilometers per hour (km/h).

Q: Can an object have a negative velocity?

A: Yes, an object can have a negative velocity. This means that the object is moving in the opposite direction of the positive direction.

Q: How do you find the acceleration of an object?

A: To find the acceleration of an object, you need to find the derivative of its velocity function with respect to time. This is because acceleration is the rate of change of velocity with respect to time.

Q: What is the relationship between velocity and acceleration?

A: Velocity and acceleration are related in that acceleration is the rate of change of velocity with respect to time. This means that if an object's velocity is changing, it must be accelerating.

Q: Can an object have a constant velocity?

A: Yes, an object can have a constant velocity. This means that the object's velocity is not changing over time.

Q: How do you find the position of an object at a specific time?

A: To find the position of an object at a specific time, you need to substitute the time into the position function.

Q: What is the unit of position?

A: The unit of position is typically measured in meters (m) or kilometers (km).

Q: Can an object have a negative position?

A: Yes, an object can have a negative position. This means that the object is located in the opposite direction of the positive direction.

Conclusion

In conclusion, we have answered some frequently asked questions about velocity and position. We have seen that velocity and speed are related but distinct concepts, and that velocity is the rate of change of position with respect to time. We have also seen that acceleration is the rate of change of velocity with respect to time, and that an object can have a constant velocity or a negative position.

References

[1] Halliday, D., Resnick, R., & Walker, J. (2013). Fundamentals of Physics. John Wiley & Sons.
[2] Serway, R. A., & Jewett, J. W. (2018). Physics for Scientists and Engineers. Cengage Learning.

Mathematical Formulas

Power rule of differentiation: if $f(x)=x^n$ , then $f'(x)=nx^{n-1}$ .
Velocity function: $v(t)=\frac{ds}{dt}$ .
Position function: $s(t)=3 t^3+4 t+9$ .

Glossary

Velocity: the rate of change of the position of an object with respect to time.
Speed: a scalar quantity that describes how fast an object is moving.
Acceleration: the rate of change of velocity with respect to time.
Position function: a mathematical function that describes the position of an object at any given time.