New riddles

Why were the inventors of the airplane correct in thinking they could fly?

A magician was boasting one day at how long he could hold his breath under water. His record was 6 minutes. A kid that was listening said, "that's nothing, I can stay under water for 10 minutes using no types of equipment or air pockets!" The magician told the kid if he could do that, he'd give him $10,000. The kid did it and won the money. How did he do it?

You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?

What did the mother broom say to the baby broom?

What do you call a calf after it's six months old?

If there are four sheep, two dogs and one herds-men, how many feet are there?

Why did the pilot sit on her alarm clock?

I can run, but not walk. Thought is not far behind me. What am I?

There is a boat with a ladder attached to it, the ladder is eight feet tall. If the water rises four feet how much of the ladder will be on top of the water?

Never ahead, ever behind, yet flying swiftly past; for a child, I last forever; for an adult, I'm gone too fast. What am I?