Heat, pressure, weather, gravity, plate tectonics--all play a part in the rock cycle.
Weathering
Mechanical weathering occurs when an applied force causes rock to break.
the force that acts on rock to change its shape or volume is stress.
The application of heat and / or pressure causes a rock to be transformed into a metamorphic rock.
When you look at a rock and see different colors, those colors are minerals .The pressure and heat causes the minerals in the rock to change into different minerals which cause the different colors in the rocks.
Pressure and/or Heat act on a rock to change it
The stress force that causes a mass of rock to pull or twist in opposite directions is called tension. Shearing is the stress force that causes a mass of rock to pull or twist in opposite directions.
Compressive stress causes the "crumpling" and folding of rock layers.
Shape of rock also changes because of stress. It causes the rock to change its shape. When a lot of pressure applies it causes the rock to change its shape.
Pushing requires energy
The forces that causes rock layers to move are; 1. Tensional Force. 2. Compressional Force. 3. Quiescent Force.
Mechanical change