Period+2+Exploring+Friction+Group+3

Together with your group, come up with a name for your group in the spirit of our physics unit!
 * Exploring Friction **
 * Our Group Name:** The Frictioners (Acacia, Zack, Shelby)


 * Work through this lab as a group. Try to encourage everyone to be involved, have a voice, and use their skills!**

"the resistance that one surface or object encounters when moving over another." "the action of one surface or object rubbing against another."
 * What is the definition of friction?**


 * Define these two types of friction:**
 * Static Friction –** //Friction between two objects in contact that are not moving.//
 * Sliding Friction –** //surface resistance to relative motion, as of a body sliding or rolling. the rubbing of the surface of one body against that of another.//

Use the blocks, masses, and spring scale to make observations on the amount of force needed to get a mass moving and the amount of force needed to keep the mass moving. Write down your observations.
 * Observations:**
 * all the blocks are cut around the same size
 * Block 4 weighs 95.3 grams
 * All blocks have different weights
 * All blocks have a light color
 * Block feels the heaviest

Spring scales measure force. Weight is the force on an object due to gravity but a spring scale can also measure the force needed to pull an object. If the spring scale reads 100 g it means that the force is about 1 N. If the spring scale reads 200 g it means that the force is about 2 N.
 * About the spring scale –**

A triple beam balance measures mass in grams. Since w=mg where w is weight in N, m is mass in kg, and g is 9.8 (acceleration due to gravity) then we can convert the mass on our balance to weight using the formula below. Weight (N) = Mass (kg) X 9.8 or Weight (N) = Mass (g) X 0.0098
 * About the triple beam balance –**

1. Experiment by pulling the block with the hook using the spring scale. Lay the block down on the table so that the largest surface is in contact with the table. Try applying such a small force that the block doesn’t move. What did the scale read when the block just begins to move? __g =__ N //This number represents the force of static friction between the block and the table.//
 * Conduct an Experiment**

2. Continue pulling the block across the table at a steady speed. What did the scale read as you pulled the block at a steady speed? __g =__ N //This number represents the force of sliding friction between the block and the table.//

3. Create a data table to record the forces of static and sliding friction as you increase the mass of the blocks/objects you pull across the table. Be sure to convert the mass to weight using the formula above. Create another row for each set of blocks you pull.
 * Objects || Mass (g) || Weight (N) || Static Friction (N) || Sliding Friction (N) ||
 * Block 1 || 117.7 || 0.11 || 0.1 || 0.2 ||
 * Blocks 1+2 || 224.9 || 2.20 || 0.6 || 0.4 ||
 * Blocks 1+3 || 354.3 || 3.47 || 0.6 || 0.4 ||
 * Blocks 1+2+3+4+5 || 559.12 || 5.48 || 1.6 || 1.0 ||

4. Stop and analyze the data in your table. Describe the relationship between the weight of the objects you pulled and each type of friction. What is the pattern seen in the table?

5. Create a graph to show the relationship.
 * Identify the independent variable for the x- axis:
 * Identify the dependent variable for the y-axis:
 * What type of graph is appropriate for this set of data?
 * What can be done to distinguish the static friction data set from the sliding friction data set?
 * Create the graph using “Create a Graph” or paper and pencil.

6. Stop and analyze the graph of your data. Describe the correlation between the weight of the objects you pulled and each type of friction. How is the correlation shown in the graph?

Acacia

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Your Turn Choose a question from below or develop your own unique question with your lab group. Design and conduct an experiment to help find the answer to the question. Complete an experimental design diagram and have it approved before beginning. a. How would the amount of static and sliding friction change if the bottom block was placed so the smaller surface was in contact with the table? b. How would the amount of static and sliding friction change if the blocks were placed on a different surface?

__Experimental Design Diagram__ __Question:__ Does the amount of static and sliding frictions change on different surfaces? __Hypothesis:__ If the surface is rougher, than the static and sliding frictions will increase.
 * __Independent Variable:__ surfaces used **

(Control) ||  Construction paper  || Sweatshirt ||  Rubber surface  ||   ||
 * Levels of the IV: || Lab Table
 * Repeated Trials: || 3 || 3 || 3 || 3 ||  ||

__Dependent Variable:__ static and sliding frictions __Constants:__ block used, mass, weight, spring scale used __Procedure Diagram:__ Acacia
 * 1) hook block one up to the spring scale
 * 2) find the static friction
 * 3) find the sliding friction
 * 4) record the surface, static, and sliding frictions in the table
 * 5) repeat steps 1-4 on the different surface

__**Reviews:**__ Acacia- The difference between our lab is we only changed the surfaces of the friction and in the class experiment, we only changed the weights and masses. Zack- The surfaces that we slid the block on was changed in our experiment, rather than changing the masses and weights in the first experiment. Shelby-