Grade 10
  1. Mechanics  1.1. Dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two dimensions  1.1.3. Displacement and Distance  1.1.4. Speed and Velocity  1.1.5. Acceleration  1.1.6. Graphical representation of motion  1.1.7. Equations of motion  1.1.8. Free fall and acceleration due to gravity  1.1.9. Projectile motion  1.1.10. Relative speed  1.2. Dynamics  1.2.1. Newton's Laws of Motion  1.2.2. Inertia and mass  1.2.3. Force and its types  1.2.4. action and reaction force  1.2.5. Friction and its effects  1.2.6. Coefficient of friction  1.2.7. Circular motion  1.2.8. Centripetal force and centripetal acceleration  1.2.9. Momentum and Impulse  1.2.10. Conservation of momentum  1.2.11. Newton's third law and applications  1.3. Work, Energy and Power  1.3.1. Work done by the force  1.3.2. Work–energy theorem  1.3.3. Kinetic energy  1.3.4. Potential energy  1.3.5. Mechanical energy  1.3.6. Energy Conservation  1.3.7. Power and efficiency  1.3.8. Renewable and non-renewable energy sources  1.4. Gravitational force  1.4.1. Newton's law of universal gravitation  1.4.2. Gravitational field and field strength  1.4.3. Acceleration due to gravity on different planets  1.4.4. Kepler's laws of planetary motion  1.4.5. Orbits and satellites  1.4.6. Weight and apparent weight  1.4.7. Gravitational potential energy
  2. Properties of matter  2.1. States of matter  2.1.1. Solid, liquid and gas  2.1.2. Molecular structure of matter  2.1.3. Intermolecular forces  2.1.4. Plasma and Bose–Einstein condensate  2.2. Pressure  2.2.1. Definition of Pressure  2.2.2. Pressure in liquids  2.2.3. Atmospheric pressure  2.2.4. Pascal's principle  2.2.5. Archimedes' Principle and Buoyancy  2.2.6. Surface tension and capillarity  2.3. Elasticity  2.3.1. Hooke's law  2.3.2. Stress and strain  2.3.3. Elastic Limit and Modulus of Elasticity  2.3.4. Applications of Elasticity
  3. Thermal physics  3.1. heat and temperature  3.1.1. Difference Between Heat and Temperature  3.1.2. Temperature scale  3.1.3. Thermal expansion  3.1.4. Thermal equilibrium  3.2. Heat transfer  3.2.1. Conductivity  3.2.2. Convection  3.2.3. Radiation  3.2.4. Insulation and its applications  3.3. Thermal properties of matter  3.3.1. Specific heat capacity  3.3.2. Latent heat and phase change  3.3.3. Boiling and Melting Point  3.3.4. Heat engines and refrigeration  3.4. Laws of Thermodynamics  3.4.1. Zeroth law of thermodynamics  3.4.2. First law of thermodynamics  3.4.3. Second law of thermodynamics  3.4.4. Carnot cycle
  4. Waves and optics  4.1. Nature and properties of waves  4.1.1. Types of waves in nature and properties of waves  4.1.2. Transverse and longitudinal waves  4.1.3. Wave parameters  4.1.4. Reflection and refraction of waves  4.1.5. Superposition and Interference  4.1.6. Standing Waves and Resonance  4.1.7. Doppler effect  4.2. Sound waves  4.2.1. Characteristics of sound waves  4.2.2. Speed of sound in different mediums  4.2.3. Applications of sound waves  4.2.4. Ultrasound and its uses  4.3. Light Waves and Optics  4.3.1. Nature of light  4.3.2. Reflection of light  4.3.3. Laws of reflection  4.3.4. Mirrors and Image Formation  4.3.5. Refraction of light  4.3.6. Snell's Law  4.3.7. Lenses and Image Formation  4.3.8. Total internal reflection and critical angle  4.3.9. Optical fibre  4.4. Optical Instruments  4.4.1. Microscope  4.4.2. Telescope  4.4.3. Human eye and vision defects  4.4.4. Camera and its working principle
  5. Electricity and Magnetism  5.1. Electrostatics  5.1.1. Electric charge and its properties  5.1.2. Conductors and Insulators  5.1.3. Coulomb's law  5.1.4. Electric field and field lines  5.1.5. Electric potential and potential difference  5.1.6. Capacitors and Capacitance  5.2. Current Electricity  5.2.1. Electric current and its measurement  5.2.2. Ohm's law  5.2.3. Resistance and resistivity  5.2.4. Series and Parallel Circuits  5.2.5. Electric power and energy  5.2.6. Kirchhoff's Laws  5.3. Magnetism and Electromagnetism  5.3.1. Magnetic field and field lines  5.3.2. Magnetic effects of electric current  5.3.3. Electromagnetic induction  5.3.4. Faraday's laws of electromagnetic induction  5.3.5. Transformers and Applications  5.3.6. AC and DC current
  6. Modern Physics  6.1. Nuclear physics  6.1.1. Structure of the atom  6.1.2. Bohr's atomic model  6.1.3. Electron Energy Levels  6.1.4. X-rays and applications  6.2. Radioactivity  6.2.1. Types of radiation  6.2.2. Half-life and radioactive decay  6.2.3. Nuclear reactions and applications  6.2.4. Fission and Fusion  6.3. Quantum physics  6.3.1. Wave–particle duality  6.3.2. Photoelectric effect  6.3.3. Energy quantization  6.3.4. Heisenberg's uncertainty principle
  7. Electronics and Communication  7.1. Semiconductors  7.1.1. Conductors, Insulators and Semiconductors  7.1.2. Diodes and their applications  7.1.3. Transistors and Logic Gates  7.1.4. LEDs and photodiodes  7.2. Communication Systems  7.2.1. Basics of communication  7.2.2. Analog and digital signals  7.2.3. Wireless and optical fibre communication  7.2.4. Radio Waves and Modulation

Grade 10 → Mechanics → Gravitational force ↓


Acceleration due to gravity on different planets


Gravity is a force that pulls objects toward one another. On Earth, we experience gravity as a force that keeps us on the ground and causes objects to fall when they fall. But have you ever wondered how gravity behaves on other planets? The concept of "acceleration due to gravity" is key to understanding this phenomenon.

Acceleration due to gravity is the rate at which an object accelerates when it is in free fall solely under the influence of gravity. This value can vary depending on the planet and is greatly affected by the mass and size of that planet.

Why is gravity different on different planets?

The force of gravity on a planet is determined by two primary factors:

  • mass of the planet
  • The distance from the center of the planet to its surface (also called the radius)

The formula describing the force of gravity is derived from Newton's law of universal gravitation:

F = G * (m1 * m2) / r^2

In this equation:

  • F is the gravitational force.
  • G is the gravitational constant, approximately 6.674 × 10^-11 N m²/kg².
  • m1 and m2 are the masses of the two interacting objects.
  • r is the distance between the centers of the two objects.

Rearranging this formula to express acceleration, we get:

g = G * M / R^2

Here, g is the acceleration due to gravity, M is the mass of the planet, and R is its radius. Note that both the mass of the planet and its radius significantly affect the value of gravitational acceleration.

Comparison of acceleration due to gravity on different planets

Let's learn how gravity varies on different planets. We will consider each planet in our solar system to understand its unique gravitational force.

Earth

Earth's gravity is the one we're most familiar with. The standard acceleration due to gravity on Earth is about 9.81 m/s². This means that if you drop an object, it accelerates toward Earth at a rate of 9.81 meters per second squared.

Earth: 9.81 m/s²

Mercury

Mercury, the planet closest to the Sun, has a much smaller mass and smaller radius than Earth. Therefore, its gravitational pull is weaker. The acceleration due to gravity on Mercury is: 3.7 m/s².

Mercury: 3.7 m/s²

Vesper

Venus has the same size and mass as Earth. Therefore, its gravity is also similar to that of Earth. Acceleration due to gravity on Venus: 8.87 m/s².

Venus: 8.87 m/s²

Mars planet

Mars, often one of the favorite destinations in science fiction, has a significantly lower gravitational pull than Earth due to its smaller size and mass. The acceleration due to gravity on Mars is: 3.71 m/s².

Mars: 3.71 m/s²

Jupiter

Jupiter, the largest planet in our solar system, has a very large gravitational force. Due to its huge size and significant mass, the acceleration due to gravity 24.79 m/s².

Jupiter: 24.79 m/s²

Saturn

Despite its large size, Saturn has a much lower density, and therefore, its gravitational pull is slightly stronger than Earth's: 10.44 m/s².

Saturn: 10.44 m/s²

Uranus

Uranus, because of its unique tilt and icy composition, has a moderate gravitational pull. The acceleration due to gravity on Uranus is: 8.69 m/s².

Uranus: 8.69 m/s²

Neptune

Neptune, known for its deep blue color, has a gravitational pull similar to that of Uranus. The acceleration due to gravity on Neptune is: 11.15 m/s².

Neptune: 11.15 m/s²

Pluto

Although Pluto has been reclassified as a "dwarf planet", it remains of interest in the field of astronomy. Due to its small size it has a very low gravitational pull, acceleration due to gravity: 0.62 m/s².

Pluto: 0.62 m/s²

Examples and applications

Understanding the variation of gravity between planets has many implications and applications, especially in fields such as space exploration and aerospace engineering. Let us consider some examples to illustrate the effect of these gravitational variations.

Example 1: Weight on different planets

The weight of an object is the force exerted on it due to gravity. It can be calculated using the formula:

Weight = Mass * g

Where Weight is in Newtons, Mass is in Kilograms, and g is the acceleration due to gravity.

Suppose the mass of an astronaut is 70 kg. We can calculate the weight of the astronaut on different celestial bodies:

  • On Earth: 70 * 9.81 = 686.7 N
  • On Mercury: 70 * 3.7 = 259 N
  • On Venus: 70 * 8.87 = 620.9 N
  • On Mars: 70 * 3.71 = 259.7 N
  • On Jupiter: 70 * 24.79 = 1735.3 N

Notice how the astronaut's weight varies considerably, showing how astronauts experience changes when traveling between different planets.

Example 2: Jumping height on other planets

Let's consider an athlete who is able to jump 0.5 m vertically on Earth. Variations due to gravity mean that this jump height varies from planet to planet.

The height of the jump can be inversely proportional to gravity:

Jump Height = (Jump Height on Earth) * (g_Earth / g_planet)

Calculations for different planets:

  • On Mercury: 0.5 * (9.81 / 3.7) ≈ 1.32 m
  • On Mars: 0.5 * (9.81 / 3.71) ≈ 1.32 m
  • On Jupiter: 0.5 * (9.81 / 24.79) ≈ 0.20 m

This demonstrates how lower gravity allows for potentially greater heights, while stronger gravity decreases the height of the jump.

Conclusion and future research

The different acceleration due to gravity in different planets provides information about the uniqueness of each planetary body. As we explore space further, understanding gravity differences will be important in planning missions, designing spacecraft, and eventually perhaps even colonizing other worlds.

The wonders of gravity extend far beyond our planet, and as our understanding deepens, so does our understanding of the universe and our potential role in it. The journey to understand the force of gravity and its implications in the universe stands as an ongoing adventure for scientific exploration.


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Acceleration due to gravity on different planets

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