Friction Lab Activity   Objective: The students will experiment with 4 different types of surfaces to determine which has the most and least friction.   Materials: pencils (4 to 6 per table), a small lightweight paperback book, metal washers, string, masking tape, large paperclips, waxed paper and sandpaper along with paper and pen or pencil for making a table Procedure: 1. Make a two column/five row table listing each surface and the number of washers it takes to move the book on that surface. 2. Tie the ends of the string to make a loop and put the string through the middle of the book. 3. Place the book on the table approximately four inches from the edge of the table. Let the loop hang down and attach a paper clip which has been bent into the shape of an s. 4. Put a washer on the paper clip and add one at a time until the book begins to move. 5. Record the number of washers needed to move the book. 6. Tape waxed paper to the table and repeat steps 3 through 5. 7. Take off the wax paper and tape down the sandpaper. Repeat steps 3 through 5. 8. Repeat steps 3 through 5, placing pencils under the book. Conclusion/Evaluation Questions 1. How does the amount of friction vary with each surface? 2. What can you conclude about how surfaces affect the amount of force needed to move an object?