Lisa, Marc, and Trini are given a puzzle. They hear a bell ring and, as instructed, put the bell in a closed jar and take out some of the air with a vacuum pump. Since they don't hear the ringing, they begin to wonder: Is the bell broken?
Lisa, Marc, and Trini are given a puzzle. They hear a bell ring and, as instructed, put the bell in a closed jar and take out some of the air with a vacuum pump. Since they don't hear the ringing, they begin to wonder: Is the bell broken?