Answer:
Yes
Explanation:
Friction is a force that opposes relative motion between systems in contact. One of the simpler characteristics of friction is that it is parallel to the contact surface between systems and always in a direction that opposes motion or attempted motion of the systems relative to each other.
Answer:
Apply Newton's second law in the moving direction.
Explanation:

Friction force applies in the opposite direction of motion; as a restriction.
It does produce 'sound' ... a compression wave traveling through the air. But your ears don't hear a sound that's vibrating less than 20 or 30 times every second. If you could swing your pendulum that fast, you could hear the sound of its vibrations pushing the air around.
Answer:
Yes, the rocks are made of matter
Explanation:
Let's remember the definition of matter.
Matter is all that has mass and occupies a place in space. Therefore, if we measure the mass of each rock we will know its mass, the other fact is that rocks like any particular body are occupying a place in an empty space.
The opposite of this is antimatter and can its extent be given by the quantum mechanics.