CBSE Class 9 Science — Work, Energy, and Simple Machines
Chapter 7 of the CBSE Class 9 Science syllabus. About 83 minutes of teaching.
Unit: Motion, Force, Work and Sound
Unit weightage: 23 marks
6 topics
What is in this chapter
- 1Work Done by a Constant Force foundation14 min
- 2Kinetic and Potential Energy16 min
- 3The Work–Energy Theorem14 min
- 4Conservation of Energy14 min
- 5Power10 min
- 6Simple Machines and Mechanical Advantage15 min
What to know first
This chapter builds on Describing Motion Around Us, How Forces Affect Motion. If any of those feel shaky, start there — the concepts below assume them.
Where the marks are
CBSE publishes marks by unit, not by chapter. The Motion, Force, Work and Sound unit carries 23 of the 80 marks in the paper, across 4 chapters. Our estimate for this chapter alone is about 6 marks — useful for deciding what to study first, but it is our split of the unit, not an official CBSE per-chapter figure.
This chapter is not on the board yet.
We author chapters one at a time and only publish once the lesson has been checked end to end, so we would rather say "not yet" than ship a thin one. The syllabus above is accurate and free to use meanwhile.
Other chapters in Class 9 Science
Cell: The Building Block of LifeTissues in ActionDescribing Motion Around UsExploring Mixtures and their SeparationHow Forces Affect MotionJourney Inside the AtomAtomic Foundations of MatterSound Waves: Characteristics and ApplicationsReproduction: How Life ContinuesPatterns in Life: Diversity and ClassificationEarth as a System: Energy, Matter, and Life