A gravitational field as a region in which an object experiences a force due to gravitational attraction.
Gravitational Field Strength
- The gravitational field strength at a point in the gravitational field is the gravitational force acting on a mass of 1 kg placed at that point.
- The unit of gravitational field strength is N/kg.
- The gravitational field strength is denoted by the symbol “g”. g= F m g = Gravitational Field Strength
F = Force acted on an object
m = mass of the object.
- The gravitational acceleration is the acceleration of an object due to the pull of the gravitational force.
- The unit of gravitational acceleration is ms-2
- Gravitational acceleratio is also denoted by the symbol “g”.
- Gravitational acceleration does not depend on the mass of the moving object.
- The magnitude of gravitational acceleration is taken to be 10ms-2.
Gravitational Field Strength vs. Gravitational Acceleration
- Both the gravitational field strength and gravitational acceleration have the symbol, g and the same value (10ms-2) on the surface of the earth.
- When considering a body falling freely, the g is the gravitational acceleration.
- When considering objects at rest, g is the Earth’s gravitational field strength acting on it.
- The weight of an object is defined as the gravitational force acting on the object.
- The SI unit of weight is Newton (N)
Differences between Weight and Mass
|Depends on the gravitational field strength||Independent from the gravitational field strength|
|Vector quantity||Scalar Quantity|
|Unit Newton (N)||Unit: Kilogram (kg)|