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Thursday, October 6, 2022

Activity 11.16 Class 9 Science Chapter 11 Work and Energy

Activity 11.16 Class 9 Science Chapter 11

 

Activity 11.16 Class 9 Science belongs to Chapter 11 Work and Energy Class 9 Science. You will get a complete solution with an explanation and conclusion. After reading activity 11.16, you will be able to answer the questions based on the activity.


Activity 11.16 Class 9 Science Work and Energy

 

You are suggested to study NCERT activity 11.16 class 9 science chapter 11Work and Energy explanation with a conclusion so that you can attempt questions based on activity 11.16 class 9 science.


Activity 11.16 Class 9 Science

   ·     Consider two children, say A and B. let us say they weigh the same. Both start climbing up a rope separately. Both reach a height of 8m. let us say A takes 15 s while B takes the 20s to accomplish the task.

   ·     What is the work done by each?

   ·     The work done is the same. However, A has taken less time than b to do the work.

   ·     Who has done more work in a given time, say in 1 s?


Calculation and explanation of Activity 11.16 Class 9 Science


Both the children climbing up means work done is against gravity.


W=mgh


Let each child weighs 25 kg 


Work done by child A in climbing a height of 8m


`W_A= mgh`= 25×10×8 = 2000J


Work done by the child B in climbing a height of 8m


`W_B= mgh`= 25×10×8 = 2000J


So we can say 


Work done by child A =Work done by child B


Now, work done per unit time by child A


(Note: rate of doing work is known as power)


`P_A=W_A/t`=  2000/15=1333.3W 

work done per unit time by child A


`P_B=W_B/t`=  2000/20=100W 


So, the power of child A is more than that of child B.


Conclusion of activity 11.16 class 9 science

This activity explains the rate of doing work.


Related Topics 

1. Activity 11.17 Class 9 Science

2. Activity 11.15 Class 9 Science

2. NCERT Solutions of chapter 11

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