Butter

Penny knew exactly what she was going to do for the 6th grade science fair.

Fact 1: Cats always land on their feet.

Fact 2: Toast always lands butter side down.

Question: What happens if you drop a cat with buttered toast attached to its back?

First she tried tying the toast to her cat. When that didn't work, she tried taping it. And when that didn't work, she tried glue.

Several pieces of toast, an angry cat, and two arms full of scratches later, Penny's only conclusion was that she wanted nothing else to do with science, ever again.