CODE/MOE/UOIT Makerspaces Project

Grade 3 - Understanding Matter & Energy

 Forces Causing Movement (Friction)

BIG IDEAS:

Forces cause objects to speed up, slow down, or change direction through direct contact or through interaction at a distance. 

Curriculum Expectations:

Overall Expectations

  • Investigate devices that use forces to create controlled movement
  • Demonstrate an understanding of how forces cause movement and changes in movement

Specific Expectations

  • 2.2 investigate forces that cause an object to start moving, stop moving or change direction
  • 2.3 conduct investigations to determine the effects of increasing or decreasing the amount of force applied to an object
  • 3.3 describe how different forces applied to an object at rest can cause the object to start, stop, attract, repel, or change direction
  • 3.4 Explain how forces are exerted through direct contact or through interaction at a distance

Learning Goals:

“We are learning to…”

  • follow the scientific method to investigate friction
  • make predictions and record findings on a chart
  • work collaboratively in a group

Success Criteria:  

“We will be successful when…”

  • we make a hypothesis or prediction about the frictional force
  • we carry out a controlled experiment

Lesson Overview: Whenever any two objects rub against each other, the force of friction tries to stop them. Sometimes two surfaces create more friction and sometimes two surfaces create less friction. In this lesson, students will learn about friction and then design and run an experiment involving pulling items over different types of flooring. Dash will be generating the power to pull the items.  

Materials and Technology:  

  • iPad
  • Dash robot
  • Piece of wood
  • Weights or heavy objects
  • Heavy elastic band and a pin to attach the elastic band to the piece of wood (alternatively a spring scale would work too)
  • Marker
  • Tape
  • ruler
  • Surfaces on which to test friction (e.g., smooth flooring, carpeting, large pieces of sandpaper)

Student Accommodations/Modifications:  

  • Students will be working in small groups due to the number of robots (Dash) available.

Lesson will be differentiated by:

  • Process, specifically: modelling the step by step instructions for attaching the elastic (or the spring scale) in order to measure the frictional force.
  • Product, specifically: students may orally provide answers to show their understanding of the concept of friction. 

MINDS ON:  Getting Started

During this phase, the teacher may:

• activate students’ prior knowledge;

• engage students by posing thought-provoking questions;

• gather diagnostic and/or formative assessment data through observation and questioning;

• discuss and clarify the task(s).

During this phase, students may:

• participate in discussions;

• propose strategies;

• question the teacher and their classmates;

• make connections to and reflect on prior learning.

Describe how you will introduce the learning activity to your students. What key questions will you ask? How will you gather diagnostic or formative data about the students’ current levels of understanding? How will students be grouped? How will materials be distributed?

Introduction of Learning Activity

Begin the activity by having students rub their hands together. Ask students the following key questions:

  • What do you notice when you rub your hands together rapidly? (feel warm)
  • Why do you think your hands started to feel warm? (rubbing)
  • Does anyone have an idea what you have created by rubbing your hands together?

Explain to students that they have created friction. Friction is created when two surfaces rub together.

Then demonstrate how you can measure a force by performing a simple activity. You will show students that by pulling a block of wood that is attached to Dash with a heavy elastic band that you can measure the frictional force by measuring how far the elastic band is stretched. (Alternatively you can use a spring scale to measure the force in Newtons).

Review the scientific method as a group (i.e., Purpose, Method, Hypothesis, Experiment, Analysis, Conclusion).

Discuss the purpose of today’s experiment (i.e., to find out the forces needed to pull a block across different kinds of surfaces) and record on a class chart outlining the Scientific Method.

Before students conduct the experiment they will receive a Friction Tester recording sheet where they will record their prediction for each different floor surface.

Student will be divided into groups of four.

ACTION:  Working on it

During this phase, the teacher may:

• ask probing questions;

• clarify misconceptions, as needed, by redirecting students through questioning;

• answer students’ questions (but avoid providing a solution to the problem);

• observe and assess;

• encourage students to represent their thinking concretely and/or pictorially;

• encourage students to clarify ideas and to pose questions to other students.

During this phase, students may:

• represent their thinking (using numbers, pictures, words, manipulatives, actions, etc.);

• participate actively in whole group, small group, or independent settings;

• explain their thinking to the teacher and their classmates;

• explore and develop strategies and concepts.

Describe the task(s) in which your students will be engaged. What misconceptions or difficulties do you think they might experience? How will they demonstrate their understanding of the concept? How will you gather your assessment data (e.g., checklist, anecdotal records)? What extension activities will you provide?

Task Description

  • Students will be engaged in using the Blockly app to run Dash in a straight line and at a speed that would be best for data collection. Discuss that in order to create a controlled experiment that all their trials will have to be done at the same speed and start at the same spot.
  • Students will determine how to attach the wooden block to Dash in order to gather the data about the length of the stretched elastic band.

Misconceptions or Difficulties

  • Through performing the experiment students may experience difficulty in setting up a controlled experiment with a constant speed. PROBING QUESTION: What happens if you program Dash to go faster and keep all other variables the same? Will it change the results?

 Demonstration of Understanding

  • filling out the Friction Tester recording sheet (rubric that outlines use of predictions and hypothesis before performing the experiment (i.e., an understanding of the Scientific Method)
  • Students will demonstrate their understanding by filling in the blanks correctly when given this sentence:  The (smoother/rougher) the surface the (greater/less) the friction and the (greater/less) the force needed to pull the wood along.
  • Observe and assess the students’ ability to cooperate within a group and do his/her share of the work
  • Observe and take anecdotal notes on the problem solving strategies used by students to ensure that the block is attached to the elastic band and to Dash. Provide students with a marker and paper and see if they can figure out how to attach a marker to the elastic band to draw a line that will record the amount of stretch in the elastic band therefore collecting the data on how much the elastic band was stretched.

Extension Activities

  • Have students design and construct a maze on a surface that will allow the wooden block to be pulled using the most or the least frictional force.

CONSOLIDATION:  Reflecting and Connecting

During this phase, the teacher may:

• bring students back together to share and analyse strategies;

• encourage students to explain a variety of learning strategies;

• ask students to defend their procedures and justify their answers;

• clarify misunderstandings;

• relate strategies and solutions to similar types of problems in order to help students generalize concepts;

• summarize the discussion and emphasize key points or concepts.

During this phase, students may:

• share their findings;

• use a variety of concrete, pictorial, and numerical representations to demonstrate their understandings;

• justify and explain their thinking;

• reflect on their learning.

How will you select the individual students or groups of students who are to share their work with the class (i.e., to demonstrate a variety of strategies, to show different types of representations, to illustrate a key concept)? What key questions will you ask during the debriefing?

Once students have completed the investigation, they will share their findings in a large group. The questions used to facilitate the discussion include:

  • What type of surface increased the amount of friction?
  • What type of surface decreased the amount of friction?

When students are responding to these questions I will ask them to refer back to the data they collected to help them use the data when they justify their understanding of friction.

If groups have different results we will spend time trying to hypothesize why the results may have been different.

Friction Tester

Record your predictions and findings

Item & Surface

Prediction

Finding

(length of stretched elastic in cm)

Wooden block on tile floor

Wooden block on carpet

Wooden block on sandpaper

Wooden block and weight on tile floor

Wooden block and weight on carpet

Wooden block and weight on sandpaper

  1. What type of surface increased the friction? _________________________________________
  2. How do you know the surface increased the friction? __________________________________

  1. What type of surface decreased the friction? _________________________________________
  2. How do you know the surface decreased the friction? __________________________________

  1. Circle the word (in brackets) to make the sentence true:

The (smoother/rougher) the surface the (greater/less) the friction and the (greater/less) the force needed to pull the wood along.

St. Ambrose Catholic School—Huron Perth Catholic District School Board

Adapted from eworkshop.on.ca