Marble Ramp Lab
Lesson 7 of 15
Objective: Students will use a marble ramp laboratory experiment to demonstrate an understanding of Work and Energy.
This lesson addresses the W.11-12.2a and HS-PS3-3 standards as a way to effectively compose a logical understanding of energy transfer mechanisms. Within this lesson, I ask students to look at energy transfer mechanisms in the context of a physical model on an inclined plane. Students construct an explanation of the connection between the release location of a marble and the horizontal displacement of a paper sail using the NGSS Practices of Developing and Using Models (SP2) and Using Mathematical, Planning and Carrying Out Investigations (SP3) and Mathematical and Computational Thinking (SP5).
Although the concepts of work and energy are not explicit in this lesson, they are embedded throughout the lesson and students often connect the main activity of this lesson to energy. Several student pairs make connections between the sail's displacement by the marble to either kinetic energy or potential energy. Students begin by observing, through a fishbowl activity, the displacement of a paper sail from a marble that rolls down an incline. Student pairs then use a set of materials to conduct their investigation, generate data and analyze the effect of the angle of the incline on the displacement of the sail. During the closure activity at the end of this lesson, I ask students to construct a short summary to demonstrate an understanding of the effect of the angle of an incline on the displacement of an object.
I assess student understanding throughout the lesson using informal check-ins and assess each student's work at the end of the school day. I want students to learn to integrate information from various points of this course into a coherent summary on the nature of energy transfer mechanisms and their connection to the work done in a system. This relates to (SP6) because students have to leverage skills like note taking to construct an explanation of energy changes within a system. One goal of this lesson is to help students learn that making and testing predictions about the behavior of a system is an essential skill for learning and practicing physics.
This portion of the lesson begins with a routine where students write the objective and additional piece of information in their notebooks as soon as they enter the classroom. I project a slide with the date, the objective and an additional prompt on the interactive whiteboard with a red label that says "COPY THIS" in the top left-hand corner. Sometimes the additional prompt is a BIG IDEA for the lesson, or the Quote of the Day or a Quick Fact from current events that is related to the lesson. The red label helps my students easily interact with the information as soon as they enter the room and avoids losing transition time as students enter the classroom.
Today's additional piece of information is a Big Idea which states that planning and carrying out investigations is an essential skill for learning and practicing physics. The objective of the bell-ringer is to give students a clear understanding of the focus of today's lesson. I choose to not give a recipe for this lab activity because I want students to learn that designing experiments is useful for studying and practicing physics.
A traditional fishbowl is a teaching strategy where students contribute to a discussion or activity. I choose a fishbowl to introduce this activity instead of a lecture or a recipe lab because I want students to craft their own labs using their observations from the fishbowl activity. I think that when students share authority over their learning process they are more likely to internalize content. I place a table in the center of the room with a set of textbooks, a marble, dominoes, a ruler and a flash card. First I create a sail by folding the flash card and taping it into a sail shape. Then I ask students for suggestions on how to use the objects on the demonstration table to make the sail move the farthest distance. Students suggest I roll the marble and try to hit the sail. I implement their suggestion and the marble misses the sail completely and bounces off of the table. Students then suggest I roll the marble on top of the ruler since it has a groove. I implement their suggestion and the marble moves in a straight line and hits the sail. Then I ask students, "Is there anything I can do to make the sail go further?" Students suggest I stack the domino case on top of the books and put the ruler on top so that it makes an angle with the table. I implement their suggestion and the sail moves a greater distance than when I roll the marble on the ruler when the ruler is flat on the table.
I ask students to spend five minutes writing down what they notice and wonder about the objects on the demonstration table. After students write down their observations, we have a whole class share out where I ask students from around the room to share their notes with the class. Student responses include, "The ruler helps keep the marble from rolling randomly around the table", "Are we creating another physics game?", "What happens when you add another textbook?", and " The marble's motion causes the flash card to move". In the next section, I ask students to create a lab that determines the relationship between the displacement of the sail and the angle of the ramp.
Design Your Own Marble Lamp
In this section of the lesson, I provide students with a set of materials and ask them to determine the effect of the incline angle upon the distance which a paper sail is driven along the level table by a rolling marble. I choose this activity because I want students to have a model for the idea that work is done when a force displaces an object. Students create a hypothesis, a method for testing this hypothesis, record data in tables and then discuss whether the data supports their hypothesis in their notebooks. I do not give students specific data to collect, I choose to give them a guiding question instead so students have authority over the lab process.
I project this slide on the interactive whiteboard at the front of the room. It takes a little longer for some students to get started than others, but after five minutes or so most students divvy up the work and quickly get to the task at hand. During the next thirty minutes, students create their own lab using the set of materials similar to the ones I use in the fishbowl in the last section of the lesson. Below is an image of a student testing the connection between incline and displacement.
As students are creating and testing their hypotheses, I walk around checking in with them. Some student hypotheses include "The distance a paper sail is driven by a rolling marble increases as the incline angle decreases." and "As the height of the ramp increases the distance a paper sail is driven by a marble increases."The purpose of this assignment is to have students solve a problem using multiple perspectives, much like scientists construct explanations of complex topics. This information is one of the three laboratory options that students may include when creating a museum exhibit on work and energy later in this unit. Below is an example of student data collection for their experiment.
Some students calculate the potential energy using the ramp height, the mass of the marble and the gravitational field strength and compare the potential energy of the marble to the distance the sail travels. Other students find the velocity of the marble and determine the kinetic energy of the marble and compare the distance the paper sail travels to the kinetic energy of the marble as it hits the sail. After thirty minutes pass, I ask for a few student volunteers to share their experience with the lab with the class. Some student comments include, "The paper sail moves farther the further up the ramp you launch the marble from.", and "As you increase the height, you increase the potential energy which changes into kinetic energy once the marble starts moving causing the sail to travel further." After this short discussion, I ask students to return the materials to the resource area at the front of the room.
I ask students to spend five minutes writing headlines that capture the most important and challenging part of the lesson for them in their notebooks. Student responses include, "Creating a sail that will catch a marble was harder than it looked in the demonstration.", "Increasing the steepness of the ruler moves the sail further down the table.", and "It was interesting to design our own lab today."
To wrap up this section of the lesson, I ask students to look at the Edpuzzle assignments and dates that I post on the class Edmodo wall. I also ask students to share their data with me during the beginning of the next class. Students spend the last five minutes of this section returning materials to the resource area at the front of the room.