Do Now Heading: What is a force? Pick up an assessment probe from the front table Open your journals and copy/answer the following question. “In your own words, how would you define and or describe a force?” Use at least 3 complete sentences and a picture to support your answer.

Today’s Vocabulary FORCE

Types of Forces

Drawing Force Diagrams A force diagram is called a Free Body Diagram (FBD) We NEED to draw these for EVERY force problem!!!

Since forces are vectors we will use arrows to show the forces Rules for Drawing FBDs Turn the object you are focusing on into a simple shape…then draw that shape Draw only the forces that are acting on the object! Since forces are vectors we will use arrows to show the forces Draw all forces as if they are acting away from the object! ( the arrow head should always point outward) Larger forces have larger arrows, smaller forces have smaller arrows

Our First FBD A box is sitting on a table. It experiences a right force of 10 N and a left force of 15 N.

Practice FBDs A man is pushing a box to the left with a force of 35 N. Draw the FBD of the box A dog is sitting on a table. He experiences a downward force of 20 N and an upward force of 10 N. Draw the FBD of the dog A box is being pulled the left with a force of 15 N and it is being pulled up with a force of 6 N. Draw the FBD for the box A man pushes a wall with a force of 5 N to the left. The wall pushes back on the man with a force of 5 N . Draw a FBD for each man.

What else can we do with FBD’s?

Fnet

In groups of 2 or 3 create the following free body diagrams with vectors and index cards and then draw it into your notebook An object with a net force of 35 N to the left An object has a force of 25 N to the right and 10 N to the left An object that had 4 forces acting on it but a net force of 50 N to the right. An object that has a net force of 0 but has 5 forces acting on it. An object with a net force of 20 N to the right, but has 6 forces acting on it.