GRAVITATION ONE SHOT PHYISCS | Class 11 Physics NCERT Explanation with Ashu Sir Science and Fun

Science and Fun Education・2 minutes read

Gravitational force, laws, equations, and calculations are discussed, emphasizing the importance of understanding gravity and its impact on objects. The text also covers Kepler's laws, escape velocity, satellite velocity, and geostationary satellites, providing insights into related concepts and formulas.

Insights

Gravitational force is the fundamental attraction between objects, directly linked to their masses and inversely related to the distance squared. Understanding this force is crucial for explaining phenomena like free fall and maintaining objects on Earth.
Kepler's Laws of Planetary Motions, introduced in the 16th century, detail how planets orbit the Sun in elliptical paths, covering equal areas in equal time intervals, and showcasing a relationship between a planet's time period and its distance from the Sun. These laws are essential in comprehending celestial motions and satellite dynamics.

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Recent questions

What is the force of attraction between objects?
Gravity is the force of attraction between any two objects in the universe.
What is the formula for gravitational force?
The formula for gravitational force is F = G * (m1 * m2) / r^2, where G is the Universal Gravitational Constant.
What is acceleration due to gravity?
Acceleration due to gravity is the rate at which an object falls under Earth's gravitational force, with a value of 9.8 m/s^2 on Earth's surface.
What are Kepler's laws of planetary motion?
Kepler's laws describe how planets orbit the Sun in elliptical paths, covering equal areas in equal time intervals, and showcasing a direct relationship between a planet's time period and its distance from the Sun.
What is escape velocity?
Escape velocity is the minimum velocity required for an object to escape Earth's gravitational force, calculated to be 11.2 kilometers per second at the surface of Earth.

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Summary

00:00

Exploring Gravity: Laws, Experiments, and Constants

Science and Fun Jahan Pay teachers with heart and mind, focusing on gravity experiments.
Series of experiments on gravity, motion, laws, energy, and rotational motion.
Lecture on gravity, subjective questions, and recorded lectures on chapters.
Gravitational force is fundamental, invisible but exists between all objects.
Gravity is the force of attraction between any two objects in the universe.
Gravitational force is directly proportional to mass and inversely proportional to distance squared.
Universal Law of Gravitation states force is proportional to product of masses and inversely proportional to distance squared.
Gravitational force formula: F = G * (m1 * m2) / r^2, where G is the Universal Gravitational Constant.
Universal Gravitational Constant (G) value is 6.67 * 10^-11 N m^2/kg^2.
Constants like Planck's constant and gas constant remain constant throughout the universe.

15:04

Gravity and Mass: Understanding Newton's Laws

Newton's distance is discussed in relation to mass in KG and Newton meter square.
The unit and dimensions of capital G are explored.
Gravitational force calculations require mass and distance between objects.
Acceleration due to gravity is explained in the context of free fall.
Free fall is defined as an object falling solely under Earth's gravitational force.
The concept of mass independence in acceleration due to gravity is highlighted.
The formula for acceleration due to gravity is derived.
The value of acceleration due to gravity on Earth's surface is calculated as 9.8 m/s^2.
The maximum value of acceleration due to gravity on Earth's surface is 9.8 m/s^2.
The decrease in acceleration due to gravity when moving above or below Earth's surface is explained.

29:39

"Gravity's Impact: Formulas for Earth's Force"

Gravitational force is essential for maintaining objects on Earth, preventing them from floating or flying.
The value of gravity, denoted as 'g,' is crucial in understanding the force's impact on objects.
The maximum value of 'g' is found at the surface of the Earth.
When calculating the value of 'g' at a height above the Earth's surface, a specific formula is utilized.
The formula for 'g' at a certain height involves the radius of the Earth and the height above the surface.
A mathematical expansion rule is applied to simplify the formula for 'g' at different heights.
The formula for 'g' at a height indicates that the value decreases as the height increases.
Exploring the impact of depth within the Earth, a new formula for 'g' at a depth is derived.
The formula for 'g' at a depth showcases how the value decreases as depth increases.
Understanding the formulas for 'g' at different heights and depths provides insights into gravitational force variations within the Earth.

43:42

"Kepler's Laws and Gravitational Potential Energy"

Multiplying leads to a decrease in g at depth, with g decreasing with height as well, indicating g's value on Earth's surface.
Derivation of two, three, and five numbers was part of board exam time, with focus on large derivations for number five.
The exam format has shifted from complete derivations to partial questions, reducing chances of full derivations appearing.
Introduction of Kepler's Law of Planetary Motions, with planets orbiting the Sun and following Kepler's three laws from the 16th century.
Kepler's first law states planets move in elliptical paths around the Sun, with the Sun at one focus.
Kepler's second law highlights equal areas covered by an imaginary line connecting planets to the Sun in equal time intervals.
Kepler's third law establishes a direct proportionality between a planet's time period and its average distance from the Sun.
Gravitational potential energy is discussed, with a new formula derived to account for variations in height, emphasizing the conservative nature of gravitational force.
Work-energy principles are applied to calculate potential energy, with the formula accounting for the distance from the center of the Earth to the object's position.
The accuracy and superiority of the new potential energy formula are explained, showcasing its effectiveness in storing work done by gravitational force.

58:58

"Escape Velocity and Satellite Formulas Explained"

The importance of using constant values for accurate results is emphasized.
The formula discussed in the text is deemed superior to MGA for precision.
The chapter delves into the concept of escape velocity and its significance.
Understanding satellite velocity, time period, and Kepler's law is crucial.
The text introduces the topic of Geostationary Satellites.
Escape velocity is defined as the minimum velocity required to escape Earth's gravitational force.
The escape velocity at the surface of Earth is calculated to be 11.2 kilometers per second.
The derivation of escape velocity formula is explained in detail.
The text highlights the significance of constant fuel in rocket science for escaping Earth's gravitational force.
The formula for satellite velocity and time period is derived, showcasing the relationship between time period and distance.

01:14:31

Satellite Energy Calculation and Geostationary Orbits

Formula for calculating kinetic energy of a satellite involves the square of velocity and the height from the surface of the Earth.
Kinetic energy is half of the potential energy, with the potential energy being the negative of double the kinetic energy.
Total energy of a satellite is the sum of potential and kinetic energy, with the potential energy being subtracted twice from the kinetic energy.
Geostationary satellites orbit above the equator with a 24-hour period, appearing stationary relative to the Earth, crucial for telecommunication and broadcasting purposes.

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