INDUCTIVE THINKING MODEL

Name of Student teacher: Hema.V                                                    Standard:VIII                             Subject: Physics                                                           Date:                                                 Unit: Force                                                    Topic: Contact and Non contact Force

 

Name of the Concept:  Force

OBJECTIVES

Pupil develop observation skills

Identification of different types of forces

Generalization about the nature and characteristics of force

Pupil develop hypothesizing predicting results

PHASE 1: Data Categorization

Teacher: What causes the changes in the following situations like falling mango, apple, iron pins      attracted by magnet, pushing a table, pulling a cart etc?

Student: Force causes changes in all situations.

Teacher: Can you suggest more situations where force is applicable in our daily life?

Student: Yes, rainfall, pushing a door, free fall of feather, sweeping, pressing empty plastic bottle, earth rotating, rubbing the paper, batsman striking a ball etc.

Teacher: Can you group those examples according to their similarity?

Group A	Group B
v  Falling of mango v  Magnet attracting iron pins at vicinity v  Rain fall on earth v  Free fall of feather v  Apple falling v  Rotation and revolution of earth v   Ink flowing in a fountain pen v  Electrons revolving round the nucleus	v  Pushing a Door.   v pressing an empty plastic bottle   v  pushing a table   v  pulling a cart   v  rubbing the paper   v  piercing nail on paper         sweeping  v   batsman striking a ball           writing

PHASE 2: Interpretation of data

Teacher: Let us analyze each group of examples and know more about them. What is the      peculiarity of examples in group A?

Student: In those examples there is no physical contact between two objects

Teacher: Yes, you are right the force applied by one body on another body without contact and is noncontact force. What about group B?

Student: In the case of group B. force arise as a result of contact.

Teacher: Yes, they all are examples of contact force. Can you define contact and non contact   force?

Student: No, Teacher.

Teacher: Force is any external effort that caused an object to undergo a certain change either    concerning its movement, direction or geometrical construction. Can you define it now?

Student: Yes, Non contact force is force acting on any body without any physical contact is a force that acts at that point of contact between two objects.

Teacher: yes, you are right.

 PHASE 3:Application of generalization

Teacher:Now lets look at some more examples ,I'll give you examples of different types of forces and you must name its type.
Student: yes, teacher.

Teacher:Example 1:Charging a comb by rubbing it on hair and attraction of paper bits towards it 

Student: Non-Contact force. and beating a drum?

Teacher: yes,What about  beating a drum?

Student: Contact force.

Teacher: yes,right now stitching a cloth?

Student: Contact force.

Teacher: yes,Right attraction between positive and negative charges?

Student: Non-Contact force.

Teacher: yes,Hammering a nail?

Student: Contact force.

Teacher: yes,Oscillation of pendulum clock?

Student: Non-Contact force.

Teacher: very good,and what about rotation of planets around the sun ?

Student: Non-Contact force.

Teacher: yes, and why?

Student:Teacher. There is no contact between the planets and sun.

Teacher: yes,Excellent .And What is the matter  in the case where , a moving  cycle is suddenly stopped.

Student: Contact force.Is,nt it teacher?

Teacher: Yes,Absolutely Correct.
    So Non-Contact force is force applied on some body by another object without interaction and a Contact force is a force that acts at that point of contact between two objects.

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