Quadratic Equations and Applications

Lesson 11

Math

Unit 8

9th Grade

Lesson 11 of 15

Objective


Write and analyze quadratic functions for projectile motion and falling bodies applications.

Common Core Standards


Core Standards

  • A.CED.A.2 — Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.
  • F.IF.C.8.A — Use the process of factoring and completing the square in a quadratic function to show zeros, extreme values, and symmetry of the graph, and interpret these in terms of a context.
  • F.IF.C.9 — Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a graph of one quadratic function and an algebraic expression for another, say which has the larger maximum.

Foundational Standards

  • A.SSE.A.1
  • A.SSE.B.3.A

Criteria for Success


  1. Describe how features of a quadratic function relate to a real-world context involving projectile motion. 
  2. Write a quadratic function to represent the motion path of a free-falling object using the formula $${h(t)=-16t^2+{v_0} t+h_0}$$ for customary units and $${h(t)=-4.9t^2+{v_0} t+h_0}$$ for metric units, where $$h$$ represents the height of the object, $$t$$ represents the number of seconds, $${v_0}$$ represents the initial velocity, and $$h_0 $$ represents the height of the object at $$0$$ seconds.
  3. Compare two projectile motion situations.

Tips for Teachers


Students had a brief introduction to quadratic applications in Lesson 13 of Unit 7, and in Lesson 4 of this unit, students interpreted quadratic functions using the vertex form. In Lessons 11–13 of this unit, students delve into writing and analyzing applications of quadratic functions at a deeper level. In each application problem, students will use their understanding of quadratic functions to interpret key features in context. For example, students will solve for the roots and determine what the value of the roots mean in projectile motion problems, area problems, and revenue applications.

Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Problems

25-30 minutes


Problem 1

Suppose $${h(t)=-5t^2+10t+3}$$ is the height of a diver above the water (in meters), $$t$$ seconds after the diver leaves the springboard.

  1. How high above the water is the springboard? Explain how you know.
  2. When does the diver hit the water?
  3. At what time on the diver's descent toward the water is the diver again at the same height as the springboard?
  4. When does the diver reach the peak of the dive?

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

References

Illustrative Mathematics Springboard Dive

Springboard Dive, accessed on Aug. 18, 2017, 2:42 p.m., is licensed by Illustrative Mathematics under either the CC BY 4.0 or CC BY-NC-SA 4.0. For further information, contact Illustrative Mathematics.

Problem 2

Chris stands on the edge of a building at a height of 60 feet. and throws a ball upward with an initial velocity of 68 feet per second. The ball eventually falls all the way to the ground.

  1. Write a function to represent the height, $$h$$, of the ball after $$t$$ seconds. 
  2. What is the maximum height reached by the ball? After how many seconds will it reach that height? 
  3. After how many seconds will the ball land on the ground after being thrown?
  4. Sketch a graph of the motion of the ball. Label key features including the vertex, $${y-}$$intercept, and root(s).

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

References

EngageNY Mathematics Algebra I > Module 4 > Topic C > Lesson 23Mathematic Modeling Exercise 1

Algebra I > Module 4 > Topic C > Lesson 23 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Modified by Fishtank Learning, Inc.

Problem Set

15-20 minutes


Give your students more opportunities to practice the skills in this lesson with a downloadable problem set aligned to the daily objective.

Target Task

5-10 minutes


A softball player throws a ball with an initial velocity of 26 feet per second. The ball leaves her hand at 3 feet above the ground.

At the same time, her softball coach throws a ball with an initial velocity of 32 feet per second. The ball leaves her hand at 2 feet above the ground.

Whose ball takes longer to land on the ground after being thrown? By approximately how many seconds? Give your answer to the nearest tenth of a second. 

Additional Practice


The following resources include problems and activities aligned to the objective of the lesson that can be used for additional practice or to create your own problem set.

  • Include examples similar to the Target Task where students write equations for two similar situations and answer questions to compare features
  • Give students an equation and have them write a context for it and questions that go along with the context

Next

Write and analyze quadratic functions for geometric area applications.

Lesson 12
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Deriving the Quadratic Formula

Topic B: Transformations and Applications

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free