Gravity works with water, ice, and wind to cause erosion in many ways.
#color(blue)(Water:# Gravity works with water to cause erosion from waves. The gravity pulls the water with the combinated force of the wind to hit rocks or cliffs, and with every hit, a layer of rock or dirt comes off. Big or small, this layer still comes off, eating away at the rock until it is degraded to nothing.
#color(gray)(Ice:# Gravity works with ice because as the gravity pulls the ice, the bottom grinds on the ground below it.
Wind: Gravity works with wind because wind blown hail, snow, or sleet can hit rocks with a great force, eroding them.