What is a gravitational field?
A region of space where any object with mass experiences a force of attraction. Earth's gravitational field extends outward in all directions from its centre.
Field lines
The arrows point toward Earth's centre — the direction any mass would be pulled. Closer lines indicate a stronger field.
Equipotential lines
The dashed horizontal lines connect points of equal gravitational potential energy. Moving between them requires work done against gravity.
F = mg
Gravitational force equals mass × field strength. Notice Force stays the same at every height — g is constant near Earth's surface regardless of position.
F = mgg = 9.8 N/kg
Ep = mgh
Lifting an object stores gravitational PE. When released, GPE converts to kinetic energy (KE) as the object accelerates — watch the energy bars swap during the fall.
Ep = mghKE = ½mv²
Try it
Drag the object high up then press Drop. Change mass — Force (F = mg) scales, but g stays fixed. This shows the field acts independently of what's placed in it.