[MACRO Academy] H2 Physics Gravitational Field + Gravity Cheat Sheet

Inside the Earth, at a distance of r₁ from the center of the circle, only the inner sphere contributes to g. And hence inside earth, The work done per unit mass by an external agent in bringing a body from infinity to that point. (without a change in KE) Energy of an Object in Orbit Two point masses attract each other with a force that is proportional to the product of their masses and inversely proportional to the square of their separations. Newton’s Law of Gravitation Variation of Gravitational Field Strength g with distance r A region of space where a mass experiences a gravitational force. The Gravitational Field Gravitational Field Strength (units: Nkg⁻¹ ) The gravitational force acting per unit mass at that point. Gravitational Field H2 PHYSICS Field lines point in the direction of the force acting on a small test mass. (resultant g-field lines) Field lines are always incident perpendicular to surfaces. Field lines never cross each other. Field Lines Gravitational Potential Gravitational Potential Energy (units: Joules) The work done by an external agent in bringing a body from infinity to that point. (without a change in KE). Relationship between F, g, GPE and ɸ

Gravitational Field H2 PHYSICS Satellite in Orbits Escape Speed The minimum speed at which a body can be projected from the surface of a planet such that it reaches an infinite distance from the planet. Variation of Gravitational Potential Between 2 Masses Why is GPE & ɸ negative? Potential at infinity is taken to be zero. Negative work done by the external agent – the direction of the external force is opposite in direction to the displacement of the mass. For more FREE notes, join our Telegram @macroacademy Gravitational force provides Centripetal force.