Einar was in his office reviewing some documents about the daily production of different products.
He was surprised when the door opened and he could see little Daven "Dad, can I come in?"
Einar smiled and put the documents on the table as he stood to go to the door for his son.
Daven was quite happy when his father carried him in his arms. "Of course you can come in. There is always time for the family.
Tell me if there is anything I can help you with? "
Daven nodded and hugged Einar's neck. "I was reading the book on fluids and I remembered the toy that can be played with air.
So I decided to make one of those toys but when I turn it using a little air, it makes a strange sound.
Why is that happening? "
Einar smiled and sat on the couch while he sat his son on his leg "The air is a fluid so when it passes through the blades of the pinwheel they produce sound..."
