Mnemonics: Gravitation | Physics Class 11 - NEET PDF Download

Master the complexities of gravitation with ease! This document provides creative and efficient mnemonics for key concepts like escape velocity and Kepler's laws, ensuring quick understanding and application in numericals. Accelerate your learning journey with these memorable tools!

1. Escape Velocity

Mnemonic: "Whole Root Two Gravity Rocket Escapes at 11.2!"

• Whole Root: Indicates the square root symbol in the escape velocity formula: 
• Two: Refers to the factor of 2 in the formula.
• Gravity: Represents $g$g, the acceleration due to gravity.
• Rocket : Represents Radius of the planet ($6.37\times 10\mathrm{<sup\; style="word-break:\; break-word;\; line-height:\; 1.8;\; font-family:\; Lato,\; sans-serif;\; font-size:\; 20px;\; letter-spacing:\; inherit;\; color:\; black;">6</sup>}$m for Earth)

• Escapes: Highlights that the escape velocity is the speed needed for a rocket or object to escape Earth's gravitational pull.

• At 11.2: Refers to the approximate escape velocity of Earth, which is 11.2 km/s.

Wil be used in many numericals. So learn the formula!

2. Kepler's Laws of Planetary Motion

Mnemonic: "Planets Eat Fruits at Equal Interval 2/3 Times"

•  Planet Eat Fruits:  - Refers to Kepler's First Law: Planets move in Elliptical orbits, with the Sun at one of the Foci.
• Equal Interval - Refers to Kepler's Second Law: A line joining a planet and the Sun sweeps out Equal areas in Equal intervals of time, irrespective of the planet's position in its orbit.
•  2/3 Times" - Refers to Kepler's Third Law: The square of the planet’s orbital period (T²) is proportional to the cube of the semi-major axis (R³)

$T^2\; \backslash propto\; R^3$T² ∝ R³