Oct. 17 – Friction

Things are more fun with less friction.  Think about cooking:

Or sports:

There's definitely more friction in field hockey and it completely changes the game.
Less friction is definitely more fun!

Today I introduced the idea of friction using a demonstration in three steps:

1. A student dragged a book across a table.
2. A student dragged the same book, but I was pressing down on it.
3. A student dragged the same book, but paper was placed under it.

We could see that the book moved different in each situation.

1. The book accelerated.
2. The book accelerated less.
3. The book accelerated more.

Here are the notes:

Here are some examples of different coefficients of friction:

Then I showed you some examples of possible problems you could solve involving friction:

A straightforward problem:

A more advanced problem:

Homework

• Continue doing textbook homework as outlined in the Unit Plan.