The Vertical Velocity Function

Oct 13, 2025 by wbrum.org 110 views

Introduction

In this article, we will explore the concept of velocity and time as it relates to a ball thrown down from a balcony. We will use a given vertical velocity function to determine the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s.

The Vertical Velocity Function

The vertical velocity function is given by $V(t)=-32t-10$ , where $t$ is time in seconds. This function represents the velocity of the ball at any given time $t$ .

Understanding the Velocity Function

To understand the velocity function, let's break it down into its components. The function $V(t)=-32t-10$ has two parts: a linear term $-32t$ and a constant term $-10$ . The linear term represents the acceleration of the ball, which is constant and equal to $-32$ ft/s^2. The constant term represents the initial velocity of the ball, which is $-10$ ft/s.

The Inequality

We want to find the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s. This can be represented by the inequality:

-90 \leq V(t) \leq -58

Substituting the Velocity Function

We can substitute the velocity function $V(t)=-32t-10$ into the inequality:

-90 \leq -32t-10 \leq -58

Simplifying the Inequality

To simplify the inequality, we can add 10 to all three parts:

-80 \leq -32t \leq -48

Dividing by -32

To isolate $t$ , we can divide all three parts by $-32$ . Note that when we divide by a negative number, the inequality signs are reversed:

\frac{80}{32} \geq t \geq \frac{48}{32}

Simplifying the Fraction

We can simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 16:

\frac{5}{2} \geq t \geq \frac{3}{2}

Conclusion

In conclusion, the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s is given by the inequality:

\frac{3}{2} \leq t \leq \frac{5}{2}

This means that the velocity of the ball will be between -90 ft/s and -58 ft/s for $t$ values between 1.5 seconds and 2.5 seconds.

Discussion

This problem illustrates the importance of understanding the concept of velocity and time in physics. By using a given velocity function, we can determine the time interval for which the velocity of an object will be within a certain range. This can be useful in a variety of real-world applications, such as designing safety features for objects in motion.

Key Takeaways

The vertical velocity function is given by $V(t)=-32t-10$ .
The time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s is given by the inequality $\frac{3}{2} \leq t \leq \frac{5}{2}$ .
This means that the velocity of the ball will be between -90 ft/s and -58 ft/s for $t$ values between 1.5 seconds and 2.5 seconds.

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.

Appendix

A.1 Derivation of the Inequality

To derive the inequality, we can start with the given velocity function:

V(t)=-32t-10

We want to find the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s. This can be represented by the inequality:

-90 \leq V(t) \leq -58

Substituting the velocity function into the inequality, we get:

-90 \leq -32t-10 \leq -58

Adding 10 to all three parts, we get:

-80 \leq -32t \leq -48

Dividing all three parts by $-32$ , we get:

\frac{80}{32} \geq t \geq \frac{48}{32}

Simplifying the fraction, we get:

\frac{5}{2} \geq t \geq \frac{3}{2}

Q&A: Frequently Asked Questions

Q: What is the vertical velocity function?

A: The vertical velocity function is given by $V(t)=-32t-10$ , where $t$ is time in seconds. This function represents the velocity of the ball at any given time $t$ .

Q: What is the acceleration of the ball?

A: The acceleration of the ball is constant and equal to $-32$ ft/s^2. This is represented by the linear term $-32t$ in the velocity function.

Q: What is the initial velocity of the ball?

A: The initial velocity of the ball is $-10$ ft/s. This is represented by the constant term $-10$ in the velocity function.

Q: What is the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s?

A: The time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s is given by the inequality $\frac{3}{2} \leq t \leq \frac{5}{2}$ . This means that the velocity of the ball will be between -90 ft/s and -58 ft/s for $t$ values between 1.5 seconds and 2.5 seconds.

Q: How do I derive the inequality?

A: To derive the inequality, you can start with the given velocity function and substitute it into the inequality. Then, you can add 10 to all three parts, divide all three parts by $-32$ , and simplify the fraction.

Q: What is the significance of the inequality?

A: The inequality represents the time interval for which the velocity of the ball will be within a certain range. This can be useful in a variety of real-world applications, such as designing safety features for objects in motion.

Q: What are some real-world applications of this concept?

A: Some real-world applications of this concept include:

Designing safety features for objects in motion, such as airbags and seatbelts
Calculating the time it takes for an object to reach a certain velocity
Determining the distance an object will travel in a given time

Q: How can I use this concept in my own work or studies?

A: You can use this concept in your own work or studies by applying it to real-world problems or scenarios. For example, you could use the concept to design a safety feature for an object in motion or to calculate the time it takes for an object to reach a certain velocity.

Q: What are some common mistakes to avoid when working with this concept?

A: Some common mistakes to avoid when working with this concept include:

Failing to consider the direction of the velocity
Failing to account for the acceleration of the object
Failing to simplify the fraction correctly

Q: How can I practice and improve my understanding of this concept?

A: You can practice and improve your understanding of this concept by:

Working through example problems and exercises
Applying the concept to real-world problems or scenarios
Reviewing and practicing the concept regularly

Conclusion

In conclusion, the concept of velocity and time is an important one in physics and engineering. By understanding the vertical velocity function and the time interval for which the velocity of the ball will be between -90 ft/s and -58 ft/s, you can apply this concept to a variety of real-world problems and scenarios. Remember to practice and improve your understanding of this concept by working through example problems and exercises, applying the concept to real-world problems or scenarios, and reviewing and practicing the concept regularly.