How do rocks melt in the volcano?

Answer 1

The simple answer is, "They don't". More precisely, rock is melted under tremendous pressure deep in the Earth's crust. The huge pressure is what heats the rocks. When the pressure builds up to a certain point, the molten rock works it way up through cracks in the Earth's crust and bursts forth through the ground.

The molten rock and ash are thrown up into the sky, then fall down to the ground. The part that falls to the ground piles up after a while, and is called a volcano. The volcano is largely above ground, and does not contribute to melting the rock.

Answer 2

Rocks melt in a volcano due to the high temperatures and pressure from the magma beneath Earth's crust. When the temperature rises above the melting point of the rocks, they turn into magma, which eventually erupts onto the surface as lava.