Friday! March 11

Okie Dokie, so here is what we did in our lovely Physics class today:

After whiteboarding, Mr. Dickie gave us the definitions of kinetic and static friction:

• 
  kinetic friction ~ The force exerted on one surface by a second surface when the two forces rub against one another because one or both of the surfaces are moving (def from the book if anyone is wondering)


• static friction ~ The force exerted on one surface by second surface when there is no motion between the two forces

He also made the point that these would have different coefficients of friction when on the same surface.

Next we did a problem to find the friction force between the friction block and the board:

We also knew that the coffiecient of (static) friction was 0.45 and that the mass of the block was 0.18 kg. Using this information, here is the force diagram:

Using the tip-to-tail method we made a triangle to help us solve for friction:

To solve for the frictional force between the block and the board"

sin28= x/1.8

Ff= 0.845 N

To solve for the normal force between the block and the board:

tan28= 0.845/x

Fn= 1.6 N

Homework :

Find the frictional force using the same picture and the same given except that the angle of the board is 44.

Hopefully this helped a tiny bit, maybe?

Anyways, have a fantabulous weekend!

in response to my darling Losi: Pasqualino <3