Gravitation — Class 11 CBSE Physics revision notes
A 6-page visual revision sheet for Gravitation, 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
Gravitation in one look
one law pulls every mass toward every other, from an apple to a satellite
Kepler's laws
- law of orbits: every planet moves in an ellipse with the Sun at one focus
- law of areas: the line from the Sun sweeps equal areas in equal times
- so a planet is fastest nearest the Sun, slowest farthest away
- equal areas is angular momentum conservation: the Sun's pull is central, no torque
Kepler's law of periods
- every planet of one Sun, same constant
T^2 ∝ r^3 - for a circular orbit of radius r
T^2/r^3 = 4π^2/GM
The universal law of gravitation
- force between two point masses
F = Gm_1m_2/r^2 - universal gravitational constant
G = 6.67×10^-11 N m^2/kg^2 - always attractive, along the line joining the masses
F ∝ 1/r^2
Page 1 of 6. The full sheet, all 6 pages, opens free in the app.
What this Gravitation sheet covers
- Kepler's laws
- Kepler's law of periods
- every planet of one Sun, same constant
- for a circular orbit of radius r
- The universal law of gravitation
- force between two point masses
- universal gravitational constant
- always attractive, along the line joining the masses
- Measuring G, Cavendish's balance
- Acceleration due to gravity
- at the surface
- at height h above the surface, h ll R
- at depth d below the surface
- Going up or going down
- Rotational effect on g
- The bulge
- Gravitational potential energy
- of a mass m at distance r from mass M, zero at infinity by convention
- a climb from r_1 to r_2
- a small climb h near the surface
- Escape speed
- Earth satellites: orbit or escape
- Time period of a satellite
- circular orbit, radius r
- in terms of g and R, for a low orbit r ≈ R
- Energy of an orbiting satellite
- Weightlessness in a lift
- Weightlessness in orbit
- Geostationary vs polar
- Beyond Newton: gravity as curved space-time
- Symbols
- 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 Gravitation 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.