2018 AP Calculus AB Free Response #2

Allen Tsao The STEM Coach
3 Apr 201907:04
EducationalLearning
32 Likes 10 Comments

TLDRIn this video, Alan from Bothell STEM continues his exploration of the AP Calculus AB free-response questions from 2018, focusing on question number two. The video discusses the motion of a particle along the x-axis, its velocity, and acceleration. Alan calculates the acceleration using the derivative of the velocity function and finds the position of the particle at a specific x-value by integrating the velocity function. He also interprets the integrals in the context of the problem, explaining the difference between displacement and total distance traveled. Additionally, Alan addresses the scenario where two particles have the same velocity and demonstrates how to find the time at which this occurs. The video concludes with a review of the answer key and an invitation for viewers to engage with the content and seek further assistance through Alan's free homework help on Twitch and Discord.

Takeaways
  • ๐Ÿ“š The video is a continuation of AP Calculus AB free response questions from 2018, focusing on question number two.
  • ๐Ÿš€ Alan, the tutor, discusses a particle moving along the x-axis with a given velocity function.
  • โฐ At time T=0, the particle's position is given as x = -5/2.
  • ๐Ÿ”ข The relationship between velocity, acceleration, and the derivative is explained, with the acceleration being the derivative of velocity with respect to time.
  • ๐Ÿงฎ Alan uses a calculator to find the derivative of the given velocity function and plugs in x=3 to find the acceleration.
  • ๐Ÿ“ The position of the particle at x=3 is found by integrating the velocity function from the initial position to x=3.
  • ๐Ÿ” The integral from 0 to 3.5 of the absolute value of the velocity function is calculated to find the total distance traveled by the particle.
  • ๐Ÿค” A second particle's position is given, and the time when both particles have the same velocity is determined by setting their velocities equal and solving for time.
  • ๐Ÿ“ˆ The time when the velocities of the two particles are equal is found to be t = 1.571.
  • ๐Ÿ“ The answer key provided at the end of the video includes the acceleration, position, total distance traveled, and the time when the velocities are equal.
  • ๐Ÿ’ป Alan suggests using a calculator for the mathematical operations and recommends plotting the functions to find intersections or solving the difference for zeros.
  • ๐Ÿ“บ The video concludes with an invitation for viewers to comment, like, subscribe, and engage with Alan's additional content and homework help on Twitch and Discord.
Q & A
  • What is the subject of the video that Alan is discussing?

    -Alan is discussing AP Calculus, specifically focusing on free response questions from the 2018 exam.

  • What is the initial position of the particle mentioned in the video?

    -The initial position of the particle is given as x equals negative five.

  • What is the formula for the velocity of the particle in the problem?

    -The velocity of the particle is given by the formula 10 sine(0.4x^2) / (x^2 - x + 3).

  • How does Alan calculate the acceleration of the particle?

    -Alan calculates the acceleration by taking the derivative of the velocity function with respect to x and then evaluating it at x equals 3.

  • What is the position of the particle at x equals three?

    -The position of the particle at x equals three is found by integrating the velocity function from the initial position to x equals three and then subtracting the initial position. The result is approximately -1.76.

  • What does the integral of the velocity function from 0 to 3.5 represent?

    -The integral of the velocity function from 0 to 3.5 with the absolute value represents the total distance traveled by the particle.

  • How does Alan determine when the two particles have the same velocity?

    -Alan finds when the two particles have the same velocity by setting their respective velocity functions equal to each other and solving for the time t when they intersect.

  • What is the value of t when the two particles have the same velocity?

    -The value of t when the two particles have the same velocity is approximately 1.57.

  • What does the integral of the velocity function from 0 to 3.5 with the absolute value signify?

    -The integral of the velocity function from 0 to 3.5 with the absolute value signifies the total distance traveled by the particle during that time interval.

  • What is the difference between displacement and total distance traveled?

    -Displacement is the straight-line distance from the initial to the final position, while total distance traveled is the entire length of the path taken by the particle, regardless of direction.

  • How does Alan use technology to assist with the calculations?

    -Alan uses a calculator to compute derivatives and integrals, which he mentions is not a common practice for him, but is necessary for solving the problem at hand.

  • What are the units for the acceleration calculated by Alan?

    -The units for acceleration are not explicitly stated, but typically they would be in units of distance over time squared, such as meters per second squared (m/s^2).

  • What additional resources does Alan offer for those interested in further help with homework?

    -Alan offers free homework help on platforms like Twitch and Discord for those who need additional assistance.

Outlines
00:00
๐Ÿ˜€ Analysis of AP Calculus Free Response Question from 2018

In this paragraph, Alan from Bothell STEM continues solving an AP Calculus AB free response question from 2018. He starts by calculating the acceleration of a particle using its velocity function and then finds its position at a specific time. Alan clarifies the initial position and integrates the velocity function to determine the particle's position. He also discusses the interpretation of integrals in the context of displacement and total distance traveled.

05:04
๐Ÿ˜€ Finding Time of Same Velocity for Two Particles

This paragraph deals with determining the time at which two particles moving along the x-axis have the same velocity. Alan compares the velocity functions of the particles and finds their intersection point, indicating when their velocities are equal. He discusses two methods of finding this time: plotting the functions separately and finding the intersection or subtracting the functions and finding the zeros. The intersection occurs at t = 1.571. Alan verifies the results with values from an answer key.

Mindmap
Keywords
๐Ÿ’กAP Calculus
AP Calculus is a rigorous high school mathematics course that covers topics in both differential and integral calculus. It is designed to prepare students for college-level mathematics and is often associated with the AP Exam in Calculus, which can earn students college credit. In the video, Alan is discussing free response questions from the 2018 AP Calculus exam, indicating the video's educational focus on advanced mathematics.
๐Ÿ’กFree Response Questions
Free response questions are a type of question found on certain standardized tests, such as the AP Calculus exam, where students must provide a detailed, written response rather than selecting an answer from multiple choices. These questions assess a student's ability to apply knowledge and solve problems, often requiring a deeper understanding of the subject matter. In the context of the video, Alan is working through these types of questions to demonstrate problem-solving strategies.
๐Ÿ’กVelocity
Velocity is a physical quantity that refers to the speed of an object in a particular direction. It is a vector quantity, meaning it has both magnitude and direction. In the video, Alan discusses the velocity of a particle moving along the x-axis, which is given by a specific function. Understanding velocity is crucial for analyzing the motion of the particle in the problem.
๐Ÿ’กAcceleration
Acceleration is the rate of change of velocity over time. It indicates how quickly the velocity of an object is changing. In the context of the video, Alan calculates the acceleration of a particle by taking the derivative of the velocity function with respect to time. This is a key step in understanding the dynamics of the particle's motion.
๐Ÿ’กDerivative
In calculus, a derivative represents the rate at which a function is changing at a given point. It is a fundamental concept used to find the slope of a tangent line to a curve or to determine the instantaneous rate of change. Alan uses derivatives to find the acceleration of the particle, which is the derivative of the velocity function.
๐Ÿ’กIntegral
An integral in calculus is a way to find the accumulated quantity of a substance or the area under a curve. It is the reverse process of differentiation. In the video, Alan uses integrals to find the position of the particle and the change in displacement, which is the integral of the velocity function over time.
๐Ÿ’กDisplacement
Displacement is the change in position of an object. It is a vector quantity that refers to the shortest path between the initial and final positions, regardless of the actual path taken. In the video, Alan calculates the displacement of the particle by integrating the velocity function from the initial time to a given time and then adjusting for the initial position.
๐Ÿ’กTotal Distance Traveled
Total distance traveled refers to the entire length of the path taken by an object, regardless of direction. It is a scalar quantity. In the video, Alan differentiates between displacement and total distance by calculating the latter using the integral of the absolute value of the velocity function, which gives the magnitude of the path taken without regard to direction.
๐Ÿ’กAbsolute Value
The absolute value of a number is its non-negative value, essentially its distance from zero on the number line, without considering which direction from zero the number lies. In the context of the video, Alan uses the absolute value to calculate the total distance traveled by the particle, which involves taking the integral of the velocity function's absolute value.
๐Ÿ’กParticle
In physics, a particle is an object whose size and shape are not considered in the analysis of its motion. It is treated as if all its mass is concentrated at a single point. In the video, Alan discusses the motion of a particle along the x-axis, using calculus to analyze its velocity, acceleration, and position.
๐Ÿ’กTwitch and Discord
Twitch and Discord are online platforms often used for gaming and social interactions. In the context of the video, Alan mentions offering free homework help on these platforms, indicating that they can also be used for educational purposes, including live streaming study sessions and providing a space for students to ask questions and receive help.
Highlights

Alan from Bothell STEM is coaching AP Calculus AB free response questions from 2018.

The focus is on question number two involving a particle moving along the x-axis with a given velocity function.

The particle's acceleration is derived from the velocity function using calculus.

The acceleration at x=3 is calculated to be -2.118 with no units.

The position of the particle at x=3 is found by integrating the velocity function from the initial position.

The integral of the velocity function from 0 to 3 gives the change in displacement of the particle.

The integral from 0 to 3.5 with the absolute value of the velocity function gives the total distance traveled.

A second particle's position is given, and the time when both particles have the same velocity is sought.

The velocity of the second particle is the derivative of its position function.

The time when the velocities are equal is found by plotting or taking the difference of the two velocity functions.

The intersection of the two velocity functions occurs at t=1.571, indicating the same velocity for both particles.

The answer key is checked against the calculated results for accuracy.

The displacement of the particle and total distance traveled are confirmed to be 2.84 and 3.737 respectively.

Alan offers free homework help on Twitch and Discord for further assistance.

The video concludes with an invitation to leave comments, likes, or subscribe for more content.

The importance of understanding the context and meaning of each integral in the problem is emphasized.

The use of a calculator for derivatives is highlighted as an alternative method in the problem-solving process.

The process of finding the initial position and change in displacement is demonstrated step by step.

The significance of evaluating the integrals at specific points to find the position and distance is explained.

The method of finding the time when two particles have the same velocity using calculus is illustrated.

Transcripts
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