Work, Energy and Power — Class 11 CBSE Physics revision notes
A 7-page visual revision sheet for Work, Energy and Power, written for Class 11 CBSE Physics. Formulas, diagrams and the traps that cost marks, laid out to be read the night before rather than the term before. Free, and it opens inside CapCompass.
Page 1 as PDF
Work, Energy and Power in one look
work loads energy in, power says how fast, collisions decide what is left after
Work, defined properly
- work needs a force and a displacement along it
- only the part of F along the motion does work
- across the motion: none. work is a scalar: +, − or 0
- lifting: you +, gravity −. pushing: you +, friction −
Work, the numbers
- a constant force, angle θ to the displacement
W = Fcdotd = Fdcosθ - the part of F that works
F_∥ = Fcosθ - you lift a body a height h, steadily
W_you = +mgh - gravity, over that same lift
W_g = -mgh
Kinetic energy and the theorem
- kinetic energy
K = 1/2mv^2 = p^2/2m - net work equals the change
W_net = Δ K = K_f - K_i - braking with a steady force f over d
-fd = 0 - 1/2mv^2
The work-energy theorem
- the net work on a body is the change in its kinetic energy
- it holds for any force, constant or changing, on any path
- add the work of every force: the net force sets the change
Page 1 of 7. The full sheet, all 7 pages, opens free in the app.
What this Work, Energy and Power sheet covers
- Work, defined properly
- Work, the numbers
- a constant force, angle θ to the displacement
- the part of F that works
- you lift a body a height h, steadily
- gravity, over that same lift
- Kinetic energy and the theorem
- kinetic energy
- net work equals the change
- braking with a steady force f over d
- The work-energy theorem
- A force that changes: the area is the work
- Conservative and non-conservative forces
- Variable force, spring
- work of a changing force
- the spring's restoring force
- work to stretch it by x, from rest
- block and spring, no friction
- Potential energy and bookkeeping
- near the ground, height h
- the conservative force does the work
- the force from the slope of U
- with heat Q lost
- a drop of height h from rest
- Conservation of mechanical energy
- Round a vertical circle
- Vertical circle at a glance
- The energy of a spring
- Equilibrium, read from U(x)
- Power: how fast the work is done
- What each collision keeps
- Collisions in one dimension
- momentum, always
- the coefficient of restitution
- first body after
- second body after
- Named special cases
- Collisions in two dimensions
- Where collisions are used
- Traps that cost marks
- Tricks that save time
How CapCompass uses this sheet
These notes are not a standalone PDF. CapCompass plans Physics chapter by chapter against your real exam dates and free hours, and when the plan reaches Work, Energy and Power the sheet opens inside the study block itself — at the page covering the sub-topic that block is on, with the timer still running. Revision arrives at the moment the plan says revise, instead of having to be gone looking for.