System of Particles and Rotational Motion — Class 11 CBSE Physics revision notes
A 8-page visual revision sheet for System of Particles and Rotational Motion, 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
System of Particles and Rotational Motion in one look
the whole body moves like its centre of mass, and spins about it too
Centre of mass
- the CM is the one point where the whole mass may be taken to sit
- two masses: it lies between them, nearer the heavier one
- a hung body settles with its CM straight below the nail
- the CM can lie outside the body: a ring's is at its empty centre
Locating the CM
- particles in space
R = fracΣ m_ir_iM - two particles on a line
x_cm = m_1x_1+m_2x_2/m_1+m_2 - a continuous body
x_cm = 1/M∫ x dm
Momentum of a system
- total momentum
P = Σ m_iv_i = MV_cm - Newton's second law
F_ext = MA_cm = fracdPdt - no external force
V_cm = constant
Motion of the CM
- the CM moves as if all the mass sat there and all external forces acted there
- internal forces cancel in pairs: they never move the CM
- a bursting shell: the CM keeps the same parabola
Page 1 of 8. The full sheet, all 8 pages, opens free in the app.
What this System of Particles and Rotational Motion sheet covers
- Centre of mass
- Locating the CM
- particles in space
- two particles on a line
- a continuous body
- Momentum of a system
- total momentum
- Newton's second law
- no external force
- Motion of the CM
- Moment of inertia
- CM of standard bodies
- Standard bodies
- The two axis theorems
- parallel axes, any rigid body
- perpendicular axes, flat lamina only
- Kinds of rigid-body motion
- Angular velocity
- Rotational kinematics
- constant α
- angle turned
- no time
- The vector product
- Torque
- turning effect of a force about O
- magnitude: zero for a force through O, or along r
- Angular momentum
- a particle about O
- rigid body, fixed axis
- torque and angular momentum
- Equilibrium of a rigid body
- Rotational dynamics: line and turn
- Rotational kinetic energy
- Angular momentum is conserved
- Rolling, slipping and skidding
- rolling without slipping
- acceleration down a slope
- Struck rod: impulse about the pivot
- 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 System of Particles and Rotational Motion 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.