Difference between revisions of "Baseball and string activity to find the surface area of a sphere"

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(Created page with "=== Objectives === Content objectives - what content areas Skill objectives - what specific skills Classroom objectives - to demo peer learning, to make a classroom resourc...")
 
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===Estimated Time===
 
===Estimated Time===
 +
1 hour
  
 
=== Prerequisites/Instructions, prior preparations, if any ===
 
=== Prerequisites/Instructions, prior preparations, if any ===
 +
Circles should have been covered.
  
 
===Materials/ Resources needed===
 
===Materials/ Resources needed===
 +
Baseballs, string, marker pens, scale, scissors and chart paper
 +
 
===Process (How to do the activity)===
 
===Process (How to do the activity)===
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How to do the different steps of the activity?
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*Process:
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#Divide the class into groups and give each group a baseball and string.
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What kinds of questions you can ask for that activity
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#Ask the students to lay flat the string around the widest part of the baseball and mark.
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#The meaured length would be the circumference.
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What are the student follow-up activities/ questions you can give?
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#The measurement will be divided by pi to find the diameter (Remember: circumference/diameter = pi).
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#The diameter divided by 2 would be the radius. Note down the radius.
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Categories: (Subject) (Topic) (Sub-concept/topic) (Class 6) (Resource format)
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#Now take a long piece of string and carefully wind it around the entire surface of the ball taking care not to overlap.Cut and discard the extra string.
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#Next unwind the string,measure it using a measuring tape. This measure would be teh surface area of the sphere.
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Example -  (Mathematics) (Triangle) (Area) (Perimeter) (Class 6) (Class 8) (Geogebra) (Video)
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To understand the formula <math>4πr^2</math> for deriving surface area of a sphere :
 +
#Consider the length of string obtained from step 7 , divide it into exactly 4 equal parts.
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#Make a circle with each part. Measure the radii.''( Hint: Can draw circle of radius from step 5 and lay the string around it)''
 +
#Observe that 4 circles would be equal and the radii in all 4 cases would be the same as the radius of sphere (derived initially by measuring circumference).
 +
#The length of string covering the entire surface area of the sphere has been formed into 4 circles of equal radius.
 +
#The area of 1 circle is <math> πr^2</math>
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#The area of 4 such circles would be 4 times the area of such circle.
 +
#Hence teh area of a sphere would be <math>4πr^2</math>
 +
*Developmental Questions
 +
*Evaluation
 +
*Question Corner

Revision as of 11:22, 24 May 2019

Objectives

Content objectives - what content areas

Skill objectives - what specific skills

Classroom objectives - to demo peer learning, to make a classroom resource, etc -

All these kinds of objectives need not be there for every activity. And no need to list them as different headings. This is only for our reference when we are developing activities.

Estimated Time

1 hour

Prerequisites/Instructions, prior preparations, if any

Circles should have been covered.

Materials/ Resources needed

Baseballs, string, marker pens, scale, scissors and chart paper

Process (How to do the activity)

  • Process:
  1. Divide the class into groups and give each group a baseball and string.
  2. Ask the students to lay flat the string around the widest part of the baseball and mark.
  3. The meaured length would be the circumference.
  4. The measurement will be divided by pi to find the diameter (Remember: circumference/diameter = pi).
  5. The diameter divided by 2 would be the radius. Note down the radius.
  6. Now take a long piece of string and carefully wind it around the entire surface of the ball taking care not to overlap.Cut and discard the extra string.
  7. Next unwind the string,measure it using a measuring tape. This measure would be teh surface area of the sphere.

To understand the formula Failed to parse (syntax error): {\displaystyle 4πr^2} for deriving surface area of a sphere :

  1. Consider the length of string obtained from step 7 , divide it into exactly 4 equal parts.
  2. Make a circle with each part. Measure the radii.( Hint: Can draw circle of radius from step 5 and lay the string around it)
  3. Observe that 4 circles would be equal and the radii in all 4 cases would be the same as the radius of sphere (derived initially by measuring circumference).
  4. The length of string covering the entire surface area of the sphere has been formed into 4 circles of equal radius.
  5. The area of 1 circle is Failed to parse (syntax error): {\displaystyle πr^2}
  6. The area of 4 such circles would be 4 times the area of such circle.
  7. Hence teh area of a sphere would be Failed to parse (syntax error): {\displaystyle 4πr^2}
  • Developmental Questions
  • Evaluation
  • Question Corner
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