|1 science book||1 bucket||brown paper|
|1 loop of string||1 hook||wax paper|
|15 weights||2 pieces of masking tape|
2. Tape brown paper to one desk and wax paper to another. Leave part of one desk clear.
3. Put the loop of string around one science book.
4. Place the book about 1 inch from the edge of the desk with no paper on it. Hang the string over the edge of the desk and attach the bucket to the string with the hook.
5. Add weights to the bucket one at a time until the book moves or starts to slide. Be sure and add the weights gently. Record the number of weights needed.
6. Predict how many weights you will need if the book is on the brown paper or the wax paper.
7. Repeat the experiment with the book on the brown paper and the wax paper. Record your results.