NCERT Solutions for Class 9 – Complete Chapter-wise Study Material
11. Work and Energy is one of the most important chapters in the Class 9 Science English NCERT Solutions curriculum. This chapter plays a significant role in helping students build a strong conceptual foundation while preparing for school examinations, class tests, unit tests, half-yearly examinations, annual examinations, and CBSE board assessments. The chapter has been carefully designed according to the latest NCERT syllabus, making it an essential part of every student's study plan.
The 11. Work and Energy - Class 9 Science English NCERT Solutions available on ATP Education explain every question in a simple, accurate, and step-by-step manner. Each answer is prepared according to the latest CBSE guidelines so that students can understand the concepts clearly without confusion. Whether you are completing your homework, revising before examinations, or strengthening your understanding of the subject, these solutions provide reliable academic support throughout your learning journey.
One of the biggest advantages of studying 11. Work and Energy is that it helps students understand important concepts, definitions, examples, and textbook exercises in an organized way. Instead of memorizing answers, students learn how to develop logical thinking, improve analytical skills, and write well-structured answers in examinations. This chapter also helps improve problem-solving ability and encourages conceptual learning, which is essential for scoring higher marks in school and competitive examinations.
Our Class 9 Science NCERT Solutions cover all textbook questions, important exercise questions, and chapter-wise explanations in English Medium. Every solution is written in easy-to-understand language, allowing students to revise the chapter quickly before examinations. Regular practice of these solutions improves confidence, strengthens subject knowledge, and reduces examination stress.
Students preparing for school assessments should carefully study 11. Work and Energy because questions from this chapter are frequently asked in objective questions, short answer questions, long answer questions, competency-based questions, and case-study questions. Understanding the concepts explained in this chapter also helps students connect related topics from other chapters, making overall learning more effective and meaningful.
At ATP Education, we continuously update our Class 9 Science English NCERT Solutions according to the latest NCERT textbooks and CBSE curriculum. Students can confidently use these chapter-wise solutions for daily study, homework assistance, quick revision, examination preparation, and self-learning. By studying 11. Work and Energy thoroughly and practising every question regularly, students can strengthen their concepts, improve writing skills, and achieve better academic performance in both school and board examinations.
11. Work and Energy - Class 9 Science English NCERT Solutions
11. Work and Energy
Chapter Review
Work and Energy
Que. – Define 1 J of Work?
Ans. – When a force of 1 N moves a body by a distance of 1 m in its own direction is equal to 1 j . It is said to be work has been done.
Que. – What is kinetic energy?
Ans. – The energy possessed by a body by virtue of in motion is called kinetic energy.
Kinetic Energy of a Body = ½ mv2
Examples : - Moving objects like Bullet, Falling water, etc.
Que – What is Power? Write it’s S.I unit.
Ans. – Power is the rate of doing Work or the rate of utilizing energy. The power of an agent may vary with time. Power is denoted by English alphabet P. And its S.I unit is Watt.
Que. – Write two conditions for work to be done.
Ans. – (a) A force should act on an abject.
- the object must be displaced.
Que. – What is work?
Ans. – When the force acts in the direction of displacement is said to be work has been done. It is equal to the product of the force and displacement.
Work done = force ´ displacement.
Que. – S. I unit of work.
Ans. – Joule (J)
1 KJ = 1000J
Que. – What is Potential energy?
Ans. – The Potential energy possessed by the object is the energy present in it by virtue of its position or configuration. Such a energy is called Potential energy.
Potential energy = mgh
Examples – Pulled rubber band, stored water on height, Pulled spring, an arrow and stretched string on bow etc.
Que. - Write the law of conservation of energy.
Ans. – Energy can only be converted from one form to another. It can neither be created nor destroyed. The total energy before and after the transformation remains the same. This law is valid in all situation and transformation. That is called the law of conservation of energy. r
Que. – What is mechanical energy?
Ans. - The sum of kinetic energy and Potential energy of an object is its total Mechanical energy.
Que. – On which factors the done work on an object is depended?
Ans. – There are two factors:
- Value of applied force (f)
- Value of total displacement (s)
Que. – What is S.I Unit of commercial Energy?
Ans. – Kw/h (Kilowatt/hour )
Que. – Define 1 unit of commercial Energy.
Ans. – The consumption of electric energy by 1 kilowatt in an hour is called 1 unit.
Que – What is transformation of energy?
Ans. – When a kind of energy converts into another kind of energy is called transformation
of energy.
11. Work and Energy
Text-book Questions
Work and Energy
Que. – Define 1 J of Work?
Ans. – When a force of 1 N moves a body by a distance of 1 m in its own direction is equal to 1 j . It is said to be work has been done.
Que. – What is kinetic energy?
Ans. – The energy possessed by a body by virtue of in motion is called kinetic energy.
Kinetic Energy of a Body = ½ mv2
Examples : - Moving objects like Bullet, Falling water, etc.
Que – What is Power? Write it’s S.I unit.
Ans. – Power is the rate of doing Work or the rate of utilizing energy. The power of an agent may vary with time. Power is denoted by English alphabet P. And its S.I unit is Watt.
Que. – Write two conditions for work to be done.
Ans. – (a) A force should act on an abject.
- the object must be displaced.
Que. – What is work?
Ans. – When the force acts in the direction of displacement is said to be work has been done. It is equal to the product of the force and displacement.
Work done = force ´ displacement.
Que. – S. I unit of work.
Ans. – Joule (J)
1 KJ = 1000J
Que. – What is Potential energy?
Ans. – The Potential energy possessed by the object is the energy present in it by virtue of its position or configuration. Such a energy is called Potential energy.
Potential energy = mgh
Examples – Pulled rubber band, stored water on height, Pulled spring, an arrow and stretched string on bow etc.
Que. - Write the law of conservation of energy.
Ans. – Energy can only be converted from one form to another. It can neither be created nor destroyed. The total energy before and after the transformation remains the same. This law is valid in all situation and transformation. That is called the law of conservation of energy. r
Que. – What is mechanical energy?
Ans. - The sum of kinetic energy and Potential energy of an object is its total Mechanical energy.
Que. – On which factors the done work on an object is depended?
Ans. – There are two factors:
- Value of applied force (f)
- Value of total displacement (s)
Que. – What is S.I Unit of commercial Energy?
Ans. – Kw/h (Kilowatt/hour )
Que. – Define 1 unit of commercial Energy.
Ans. – The consumption of electric energy by 1 kilowatt in an hour is called 1 unit.
Que – What is transformation of energy?
Ans. – When a kind of energy converts into another kind of energy is called transformation
of energy.
11. Work and Energy
Additional -Questions
Work and Energy
Que. – Define 1 J of Work?
Ans. – When a force of 1 N moves a body by a distance of 1 m in its own direction is equal to 1 j . It is said to be work has been done.
Que. – What is kinetic energy?
Ans. – The energy possessed by a body by virtue of in motion is called kinetic energy.
Kinetic Energy of a Body = ½ mv2
Examples : - Moving objects like Bullet, Falling water, etc.
Que – What is Power? Write it’s S.I unit.
Ans. – Power is the rate of doing Work or the rate of utilizing energy. The power of an agent may vary with time. Power is denoted by English alphabet P. And its S.I unit is Watt.
Que. – Write two conditions for work to be done.
Ans. – (a) A force should act on an abject.
- the object must be displaced.
Que. – What is work?
Ans. – When the force acts in the direction of displacement is said to be work has been done. It is equal to the product of the force and displacement.
Work done = force ´ displacement.
Que. – S. I unit of work.
Ans. – Joule (J)
1 KJ = 1000J
Que. – What is Potential energy?
Ans. – The Potential energy possessed by the object is the energy present in it by virtue of its position or configuration. Such a energy is called Potential energy.
Potential energy = mgh
Examples – Pulled rubber band, stored water on height, Pulled spring, an arrow and stretched string on bow etc.
Que. - Write the law of conservation of energy.
Ans. – Energy can only be converted from one form to another. It can neither be created nor destroyed. The total energy before and after the transformation remains the same. This law is valid in all situation and transformation. That is called the law of conservation of energy. r
Que. – What is mechanical energy?
Ans. - The sum of kinetic energy and Potential energy of an object is its total Mechanical energy.
Que. – On which factors the done work on an object is depended?
Ans. – There are two factors:
- Value of applied force (f)
- Value of total displacement (s)
Que. – What is S.I Unit of commercial Energy?
Ans. – Kw/h (Kilowatt/hour )
Que. – Define 1 unit of commercial Energy.
Ans. – The consumption of electric energy by 1 kilowatt in an hour is called 1 unit.
Que – What is transformation of energy?
Ans. – When a kind of energy converts into another kind of energy is called transformation
of energy.
11. Work and Energy
Additional -Questions 2
Work and Energy
Que. – Define 1 J of Work?
Ans. – When a force of 1 N moves a body by a distance of 1 m in its own direction is equal to 1 j . It is said to be work has been done.
Que. – What is kinetic energy?
Ans. – The energy possessed by a body by virtue of in motion is called kinetic energy.
Kinetic Energy of a Body = ½ mv2
Examples : - Moving objects like Bullet, Falling water, etc.
Que – What is Power? Write it’s S.I unit.
Ans. – Power is the rate of doing Work or the rate of utilizing energy. The power of an agent may vary with time. Power is denoted by English alphabet P. And its S.I unit is Watt.
Que. – Write two conditions for work to be done.
Ans. – (a) A force should act on an abject.
- the object must be displaced.
Que. – What is work?
Ans. – When the force acts in the direction of displacement is said to be work has been done. It is equal to the product of the force and displacement.
Work done = force ´ displacement.
Que. – S. I unit of work.
Ans. – Joule (J)
1 KJ = 1000J
Que. – What is Potential energy?
Ans. – The Potential energy possessed by the object is the energy present in it by virtue of its position or configuration. Such a energy is called Potential energy.
Potential energy = mgh
Examples – Pulled rubber band, stored water on height, Pulled spring, an arrow and stretched string on bow etc.
Que. - Write the law of conservation of energy.
Ans. – Energy can only be converted from one form to another. It can neither be created nor destroyed. The total energy before and after the transformation remains the same. This law is valid in all situation and transformation. That is called the law of conservation of energy. r
Que. – What is mechanical energy?
Ans. - The sum of kinetic energy and Potential energy of an object is its total Mechanical energy.
Que. – On which factors the done work on an object is depended?
Ans. – There are two factors:
- Value of applied force (f)
- Value of total displacement (s)
Que. – What is S.I Unit of commercial Energy?
Ans. – Kw/h (Kilowatt/hour )
Que. – Define 1 unit of commercial Energy.
Ans. – The consumption of electric energy by 1 kilowatt in an hour is called 1 unit.
Que – What is transformation of energy?
Ans. – When a kind of energy converts into another kind of energy is called transformation
of energy.
11. Work and Energy
Additional -Questions 3
Work and Energy
Que. – Define 1 J of Work?
Ans. – When a force of 1 N moves a body by a distance of 1 m in its own direction is equal to 1 j . It is said to be work has been done.
Que. – What is kinetic energy?
Ans. – The energy possessed by a body by virtue of in motion is called kinetic energy.
Kinetic Energy of a Body = ½ mv2
Examples : - Moving objects like Bullet, Falling water, etc.
Que – What is Power? Write it’s S.I unit.
Ans. – Power is the rate of doing Work or the rate of utilizing energy. The power of an agent may vary with time. Power is denoted by English alphabet P. And its S.I unit is Watt.
Que. – Write two conditions for work to be done.
Ans. – (a) A force should act on an abject.
- the object must be displaced.
Que. – What is work?
Ans. – When the force acts in the direction of displacement is said to be work has been done. It is equal to the product of the force and displacement.
Work done = force ´ displacement.
Que. – S. I unit of work.
Ans. – Joule (J)
1 KJ = 1000J
Que. – What is Potential energy?
Ans. – The Potential energy possessed by the object is the energy present in it by virtue of its position or configuration. Such a energy is called Potential energy.
Potential energy = mgh
Examples – Pulled rubber band, stored water on height, Pulled spring, an arrow and stretched string on bow etc.
Que. - Write the law of conservation of energy.
Ans. – Energy can only be converted from one form to another. It can neither be created nor destroyed. The total energy before and after the transformation remains the same. This law is valid in all situation and transformation. That is called the law of conservation of energy. r
Que. – What is mechanical energy?
Ans. - The sum of kinetic energy and Potential energy of an object is its total Mechanical energy.
Que. – On which factors the done work on an object is depended?
Ans. – There are two factors:
- Value of applied force (f)
- Value of total displacement (s)
Que. – What is S.I Unit of commercial Energy?
Ans. – Kw/h (Kilowatt/hour )
Que. – Define 1 unit of commercial Energy.
Ans. – The consumption of electric energy by 1 kilowatt in an hour is called 1 unit.
Que – What is transformation of energy?
Ans. – When a kind of energy converts into another kind of energy is called transformation
of energy.
Science
Class 9 (English Medium)
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