Gravitational Field Strength

Key points

Gravity operates via gravitational fields.
- Every object with mass has its own gravitational field.
The gravitational field strength at a certain point is the gravitational force per unit mass experienced by a point mass at that certain point.
Gravitational field strength is equivalent to acceleration due to gravity.

Gravitational Field Strength is defined as the gravitational force per unit mass experienced by a point mass at a certain point.

Every object with mass creates a gravitational field by bending space-time to carry out the attractive force of gravity.
Gravitational Field Strength is a vector quantity whose direction is given by the direction of the force that a point mass would experience at that certain point.
- Direction in the example is toward the center of the earth, as its mass would attract a point mass within its gravitational field
- It is not uniform – it gets weaker as the distance increases.
  - Distance between the red lines increases.
- Gravitational field strength is radial around a single point or spherical mass, like the Earth.

Formula Booklet

The formula booklet equation for the gravitational field strength is based on its definition.

The gravitational force per unit mass leads to the fraction F/m.
Substituting the equation for the force of gravity and cancelling leads to the second equation.
- Only the mass of one object is needed – the one that is creating the observed force.

IB News, Covid-19 Updates, Deadlines, Tips and Tricks, and Hundreds of Free Resources are Awaiting You!