Essential Knowledge 2.B.1 🌍
A gravitational field g at the location of an object with mass m causes a gravitational force of magnitude mg to be exerted on the object in the direction of the field.
Image courtesy of mechanicaltopdc.
As pictured in the image above, Weight or Force of Gravity is always acting downwards, towards the center of a planet. If this is the only force exerted on an object, the object is said to be in free fall. If you recall from Kinematics, an object’s acceleration is equal to the acceleration due to gravity when in free fall. The variable g, or the gravitational field is subject to change based on the planet itself or the object’s location relative to the planet’s surface.
Key Concept - Gravitational Field
The influence an object has to produce a force on other objects.
Essential Knowledge 2.B.2 ☄️
The gravitational field caused by a spherically symmetric object with mass is radial and, outside the object, varies as the inverse square of the radial distance from the center of that object.
where g is the gravitational field in m/s/s, G is the universal gravitation constant 6.7 x 10^-11 N * m^2/kg^2, r is the radius in meters, and m is the mass in kilograms.
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