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.
Here i state the conservation of energy rule and use that to justify my answer. I showed how to manipulate percentages to get the final answer of 11000J (2sf). Hope I'm right xx
Answer: The statement that supports Newton's first law of motion is the one that says that planets can move at a varying speed due to forces exerted in space