Science teaching package

Teaching Presentation

Topic: Forces (Upper Block)

Specific Instructional Objectives:

• Recognize different types of forces in a single system– gravitational force, elastic spring force and frictional force (with examples)

• Investigate the effects of forces on springs and communicate findings

Pre-requisites

Students should be able to recognize that there are different components to a system

Students should be able to recognize and relate to examples of

• Gravitational force

• Elastic spring force

• Frictional force

Period Allocation

Duration

Activities Objectives

Lesson 1 (60 minutes)

Inquiry Based Learning Activity – Oscillating Woodpecker

To analyze a system and recognize the forces at work by active inquiry

To investigate the effect of friction on motion of objects and communicate findings.

Lesson 2(30 minutes)

Real World Applications – Uses and problems with friction

To identify examples of friction in daily life.

To apply friction concepts in problem solving.

Rationale

Inquiry based approach:

• Focuses on the developing of the meta-cognitive aspect of students, as opposed to rote learning.

• Conceptual understanding MUST be communicated to/elicited from students in a engaging situation which they can apply it to.

Constructivist Approach:

• Students required to pen down pre-conceptions before activity and these MUST be addressed via self-reflection or teacher-led discussions.

Rationale (II)

Concept Mapping

• A strategy for putting facts into perspective and with an emphasis on the links between them.

• A form of formative assessment

Lesson 1

Oscillating Woodpecker

Activity

- Format: Groups of 4

- Location: Science Lab

Engage

Teacher to show students a demonstration of how the oscillating woodpecker works.

Teacher to build on and elicit student response on how they think the toy works and how its speed can be varied.

Teacher to introduce the day’s activity and the accompanying activity sheet.

Explore

Students will be given instructions on how to make their own oscillating woodpecker

Students will be provided materials as below to aid investigation

• Different types of rubber bands (texture and thickness)

• Strings of different materials

• Ten cent coins as weights

• Woodpecker template

• Straws

Inquiry Questions(Pre-Activity)

Hypothesis Testing

Findings Reflections(Post class Discussion)

Forces present in system

What forces I think that are present?

Removing the element which contributes the force.

Absence of this force, system doesn’t work

Are the force(s) I identified present? Why/Why not?

Factors that affectthe speed of pecker

Factors I think will affect speed

Varying different components of the system

Measurementsof the time taken for pecker to travel

Are the factors I identified relevant? Why/Why not?

Factors specific to friction

Which of these factors directly affect friction?(Teacher-led class discussion)

Explore (II)

Students to document their investigation process (how did carried out their hypothesis testing) in space allocated in activity sheet

Students are scaffolded to adhere to sound and scientific experimental procedures where possible ( e.g. changing one variable at a time, taking multiple readings)

Note: Teacher to try and avoid planting the idea the testing of effect of surface area on friction in students. But should address concerns when raised privately.

Explain (Concepts)

Teacher-led class discussion: Each group to send 1 representative to share findings.

Using the activity, teacher to elicit following concepts:

• Friction is a force that occurs when surfaces rubs against each other.

• Friction opposes motion ( reduces speed of moving object and acts in the opposite direction)

• Friction is greater between rougher (Whiteboard)when the more strongly the surfaces are rubbed (greater force)

Explain (Procedures)

Teacher to invite the class to critique on the experimental procedures of other groups and communicate viewpoints using proper scientific terms.

Teacher to highlight key points of good procedures and explain why some are otherwise

Explain (Misconceptions)

Teacher to have pen down common misconceptions students have on the whiteboard after shuffling and looking at their activity sheets during their investigation.

Teacher invite class to relook at some of their previous viewpoints and offer explanations.

Teacher to intervene where necessary.

Explain (Difficulties)

Due to fast motion of woodpecker moving to stationary position, some students fail to appreciate that the object has slowed down. (Use of Youtube video to show slow motion)

Heavier weight should result in the woodpecker falling faster but results show otherwise. Good opportunity to highlight that friction (a result of the weight) acts in opposite direction of motion of weight)

Elaborate

Teacher to have put all the information gathered so far about friction at one side of the whiteboard.

Students to put these information into perspective and hence suitable headings using Vee Map, also documenting their experimental procedures, indicating any changes that should be or can be made to improve it based on class discussion.

Elaborate

Teacher share with the class his version of organization of the information, asking for alternatives.

Teacher to elaborate on respective headings to fill in information that was not elicited from activity (e.g. friction produces heat, friction causes wear and tear) Drawing inferences to real life examples and addressing why these have not been observed in the activity.

Students to fit these new information under suitable headings, making changes to original when necessary)

Evaluate (Cliff-hanger)

Teacher to show students a short but interesting demonstration on friction and ask them to use the concepts they have acquired to analyze the problem.

Evaluating questions (Completed in activity sheet):

What is the force at work here?

Why is it harder when more pages are overlapped?

Was did it get harder to separate the books when I used more force?

Lesson 2

Teacher to go through previous cliff hanger as a recap.

Introduce new lesson objectives: To find out real world applications and problems involving friction.

Group Activity

Teacher to bring in items/ pictures of friction at work and each group is assigned one.

Groups to identify role of friction in their object/picture and discuss the benefits/ problems friction has caused, justifying them with conceptual knowledge and terms.