Class 9 11. Work and Energy Work formula by Scientifically and Mathematically: NCERT Book Solutions

Class 9 chapter 11. Work and Energy ncert exercise questions and textual questions with solution for board exams and term 1 and term 2 exams.

NCERT Solutions

All chapters of ncert books Science 11. Work and Energy Work formula by Scientifically and Mathematically is solved by exercise and chapterwise for class 9 with questions answers also with chapter review sections which helps the students who preparing for UPSC and other competitive exams and entrance exams.

Class 9 chapter 11. Work and Energy ncert exercise questions and textual questions with solution for board exams and term 1 and term 2 exams. - 11. Work and Energy - Work formula by Scientifically and Mathematically: NCERT Book Solutions for class 9th. All solutions and extra or additional solved questions for 11. Work and Energy : Work formula by Scientifically and Mathematically Science class 9th:English Medium NCERT Book Solutions. Class 9 chapter 11. Work and Energy ncert exercise questions and textual questions with solution for board exams and term 1 and term 2 exams.

11. Work and Energy : Work formula by Scientifically and Mathematically Science class 9th:English Medium NCERT Book Solutions

NCERT Solutions ⇒ Class 9th ⇒ Science ⇒ Chapter 11. Work and Energy:

Class 9 11. Work and Energy Work formula by Scientifically and Mathematically: NCERT Book Solutions

NCERT Books Subjects for class 9th Hindi Medium

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11. Work and Energy

Class 9 chapter 11. Work and Energy ncert exercise questions and textual questions with solution for board exams and term 1 and term 2 exams.

Work formula by Scientifically and Mathematically

Positive Work, Negative Work and Zero Work

Equation of Work:

Mathematically work is expressed by the following equation.

W = F . S . cos θ

F = force, S = displacement, θ is the angle between force vector and displacement vector.

There are three situation for work done:

Positive Work: Work done is positive when the force is in the
direction of displacement.

Example of positive work:

The baby has exerted a force in the direction of displacement of the car. In this situation, the work done will be equal to the product of the force and displacement. In such situations, the work done by the force is taken as positive.

Zero Work: When after applying an amount of force but there is no displacement. Then the angle between these two vectors is 90^o.

Example: A large and heavy rock is moved by applying force but no displacement noticed, in this case work will be calculate zero.

Negative Work: Work done is negative when the force acts
opposite to the direction of displacement.

Consider a situation in which an object is being displaced by the action of forces and we identify one of the forces, F acting opposite to the direction of the displacement s, that is, the angle between the two directions is 180º. In such a situation, the work done by the force, F is taken as negative and denoted by the minus sign. The work done by the force is F × (–s) or (–F × s).