Create your own lightning with these time-tested devices that have delighted students for decades! Named after the inventor Van de Graaf, a German physicist, this machine produces low-amperage static electricity that can be shocking but perfectly safe. Two different pulleys with 2 neoprene belts inside a 1¾ plastic column create and carr
ไม่มีความคิดเห็น:
แสดงความคิดเห็น