2. Lab Zone Activity How many books can you lift with your little finger? Activity How many books can you lift with your little finger?

3. Materials Books (thin) Two pencils (and your little finger) Books (thin) Two pencils (and your little finger)

4. What To Do… Place one book on the desk. Slip your little finger under the book Try to lift the book Add another book and try to lift both books, using your little finger Continue adding books and one by one try lifting the books with your little finger until you can no longer lift with your little finger. Place one book on the desk. Slip your little finger under the book Try to lift the book Add another book and try to lift both books, using your little finger Continue adding books and one by one try lifting the books with your little finger until you can no longer lift with your little finger.

5. Next… Place one pencil along the edge of the book stack, about 2.5 cm away. Place the unsharpened end of the other pencil under the bottom book and on top of the other pencil. Using your little finger, press down on the eraser end of the second pencil and try to lift the books. Place one pencil along the edge of the book stack, about 2.5 cm away. Place the unsharpened end of the other pencil under the bottom book and on top of the other pencil. Using your little finger, press down on the eraser end of the second pencil and try to lift the books.

6. Then… Move the bottom pencil further away from the stack and try again. Repeat moving the bottom pencil further away from the books until it is near the eraser end of the top pencil. Move the bottom pencil further away from the stack and try again. Repeat moving the bottom pencil further away from the books until it is near the eraser end of the top pencil.

7. Explain Your Results… 1.What type of simple machine did you model in this activity? 2.Described what happened when you tried to lift the books with your finger. 3.How did the amount of force needed change when you used the pencil? 4.How did changing the position of the bottom pencil affect the force needed to lift the books? 1.What type of simple machine did you model in this activity? 2.Described what happened when you tried to lift the books with your finger. 3.How did the amount of force needed change when you used the pencil? 4.How did changing the position of the bottom pencil affect the force needed to lift the books?