Teachers TryScience

Kinetic Energy vs Potential Energy

May 24 2016

Source: LLF India

Summary Information

Topic:

Physics

Workplace Skills:

Secondary Research

Recording & Reporting

Target Grade (Ages):

Grade 9 (Ages 14-15)

Diversity Indicators:

Grade 9- Students

Tab Wrapper

LESSON

Goals and Prerequisites

Goals:

After this lesson, students should be able to:

Recognize that engineers need to understand different forms of energy in order to design useful products.
Explain the concepts of kinetic and potential energy.
Understand the importance of potential and kinetic energy.
Understand energy equations.

Prerequisites:

Basic understanding of concept of energy that it can change from one form into other, it can is conserved and can neither be created nor be destroyed.

Instructional Objective(s)

At the end of the lesson, students should be able to:

Recognize that engineers need to understand different forms of energy in order to design useful products.
Understand that when designing a roller coaster, mechanical and civil engineers ensure that there is sufficient potential energy (which converts to potential energy) to move the car through the entire roller coaster ride.
Use concepts of kinetic energy, potential energy and conservation of energy to perform an experiment to determine an object’s velocity.

Instructional Resources

Background:

Instructional Resources

Introduction –

Ascertain students’ prior knowledge about work and energy. Induce inquisitiveness among the students by encouraging a large group discussion about various types of work and corresponding type of energy used in it. Put forward some questions like -

How will you define energy? (Ans: Energy is the capacity to do work)
If an object is not involved in any work, will it have energy? (Ans: Yes, energy is the ability or capacity to do work, it cannot be measured by its status of doing or not doing any work)
Name different types of energy.( Ans: chemical energy, heat energy, sound energy, light energy, mechanical energy ,nuclear energy, solar energy so on).
Define mechanical energy? (Ans: Mechanical energy is possessed by a body, by virtue of its motion or position).
Is conversion of energy is possible? (Ans: Yes, it is possible to convert one type of energy to another).
What is the final conversion of energy? (Ans: The last conversion of energy in most cases is toward conversion into heat energy).
How is this conversion of energy important in our lives?(Ans: By conversion of electrical energy to light energy – e.g lighting a bulb, by conversion of mechanical energy to electrical energy – electricity produced, by conversion of solar energy to heat energy – solar cooker so on).

Conclude the discussion by showing students some videos from the following linkswhich will enhance their prerequisite knowledge for the topic:

https://www.youtube.com/watch?v=VgyXWXI-wec

www.youtube.com/watch?v=dxuG5PeNBMo

Divide the class in groups of 6 and give each group a K-W-H-L chart. Have each group fill ‘K’, ‘W’ and ‘H’ columns about potential and kinetic energy. Check and discuss K-W-H-L charts with each group.
Inform the students that they are going to design a roller coaster and build the designed roller coaster using the given material.
Working as engineering teams, students design and create model roller coaster using chart papers and tape as their construction materials.
Their goal is to build a perfect roller coasterwith a truss pattern of their own design, while meeting the design criteria and constraints. They experiment with different heights and slope to achieve sufficient kinetic energy to move the marble ball through the entire roller coaster ride. Let the competition begin! Read more about truss pattern here -http://www.mdcoveredbridges.com/trusses.html
Pass the set of required stationary and material to each group.
After the roller coaster is constructed they need to measure the velocity of the marble ball as instructed in the workbook and record the readings.

Integration with other STEM Subjects

Mechanical engineers are concerned about the mechanics of the energy - how it is generated stored and moved. Design and manufacture engineers apply the principles of potential and kinetic energy when they design consumer products. When designing a roller coaster they ensure that there is sufficient potential energy (which will be converted into kinetic energy) to move the cars through the entire roller coaster ride.

Integration with Math for calculations.

Integration with English to write the observation in Workbooks.

Materials:

Material Needed

For each student:

Engineering Design Process Workbook.
Handout for students needing assistance to build the bridges
KWHL Chart: http://coolaustralia.org/wp-content/uploads/2013/03/KWHL1.jpg

For each group:

Chart paper
Cellophane tape
Masking tape
Scissor
Measuring Scale
Rounder
Marble balls
Glue stick

Handout for students

Procedure:

Engineering Designing/STEM Based Project

Introduction

To begin, you may want to introduce students to roller coaster which falls under design and manufacturing Engineering with the video linksgiven below.

https://www.youtube.com/watch?v=4f1bND-MhuY

https://www.youtube.com/watch?v=LrRdKmjhOgw

Part1 – Students learn about Roller coaster and Design one of their own.

Ask students to watch video clippings about designing of various parts of a roller coaster.

https://www.youtube.com/watch?v=4lnWb64z2jw

https://www.youtube.com/watch?v=8SO9NTQ1Q6Q

https://www.youtube.com/watch?v=aPgfYpd6UCc

https://www.youtube.com/watch?v=9aP2FQoRxho

After going through some/all video clips tell students that today they are a group of design and manufacturing engineers and they have been asked to design and simultaneously build a roller coaster for the city amusement park. So they will begin designing a paper marble roller coaster model and ensure that there is sufficient potential energy to move a marble through the entire roller coaster.

Let the students sit with their respective teamsto brainstorm ideas, make sketches, and choose a final design for their roller coaster. Also ask them to choose a name for their design team.
Provide them time to work on their design keeping the strength, length, height among other parameters in mind. Guide them to work backwards on how much material they need to work with (that is the material they have), the constraints, to be able to make the most of the little given!
Before they begin making the actual design, assemble them anddiscuss the following rules:
- The only materials students may use for the roller coaster are chart papers and cellophane tape.
- Their roller coaster will be judged on its capability of moving of the marbles through theroller coaster and the velocity it will achieve. The endurance of each team’s roller coaster will be tested and if they fail they may need to redesign it.
If the students need help at any point, they should refer to the handbook given to them.
Each student should note their engineering process in their respective workbooks.

Part – 2 -Constructing the roller coaster

Instruct and encourage each team to distribute their workload evenly among the members for timely completion of the project.
The students and teams who need assistance can be guided with useful inputs which are available to the teacher.
While constructing the roller coaster they need to keep in mind the height and types of structures of the roller coaster and how much velocity the marbles will attain. (Teacher can keep kindling their imagination by asking questions)
Instruct them to be careful while dealing with the scissors.

Part – 3 –Roller coaster testing and redesigning

Provide students time to make a presentation of their models with an interesting name and details.
Again orient students on the timeline and the roles for each student.
Have students test their roller coaster by measuring the velocity of the marble.
Students will follow their noting in the workbook to find the velocity of the marble.
Path of the marble should be stream lined. If the flow is not streamlined students will rethink and redesign their roller coaster .Then they will again measure the velocity of the marble.
Students should measure the velocity of the marble at least for 3 times.
A question answer round is conducted for the students led by the teacher
- Students should be encouraged to speculate about why some roller coaster are more safe than others.
- What factors went into determining the strength or weakness of the roller coaster?
- What flaws were inherent in the building materials? How were those flaws overcome?
To conclude, ask students to answer the summative questions in the workbook.

Culminate the activity by asking students to reflect on the entire design process. Have students fill in the L column of the K-W-H-L

Ask students to note all the real-world applications in which they see conservation of mechanical energy in the systems. Possible examples: simple pendulum, bow and arrow, pressing a spring etc.
Students can work on engineering processes for other types of projects like water supply to a city by maintaining a sufficient height of the water tank.

Rubric Presentation

Assessments and Rubrics

Pre-activity – Discussion questions

How do you think the people in ancient times made huge monuments without the knowledge of numbers and shapes?
Today, where and how is maths used in civil engineering?
Why are bridges an important aspect of our progress and development?
Why do we usually see bridges made of triangles?
Describe ways that technology can be used to make monitoring and inspection of bridges more efficient and effective assuming the Indian government requires states to inspect and rate all bridges at least once every two years.

Activity Embedded – (Formative Assessment)

Prediction: Before testing, ask teams to predict how much weight of the marble will collapse their roller coaster. Record predictions on the board.
Evaluate the student handbook to gauge the mastery of the concept (Reviews attached in the workbook)

Post activity –

Show and test – Evaluate the student’smodel and involvement in the given task using the given rubric.
Assessment- Evaluate the students understanding and application in the given summative assignment.

Engineering Activity

Rubric Presentation

Credits

Credits

RESOURCES