Simple Machines Lab Activity Purpose: Station #1: Classes of ...

Simple Machines Lab Activity Purpose: Station #1: Classes of Levers Go to page 428-429 of your text book. Give an example of each type of lever and draw a picture of each (make sure to label input force, output force, and fulcrum!)

Class 1 Example:

Class 2 Example:

Class 3 Example:

Station #2: Levers and fulcrums 1. Put a pencil under the 80 cm mark of a meter stick to act as a fulcrum. 2. Place one mass at the 0 cm mark. Hang the spring scale on the other end, off the edge of the table. Pull down and record the force needed to lift the mass in your data table. 3. Repeat step 2 with two masses. 4. Repeat step 2 with three masses. 5. Move the pencil so that it is under the 60 cm mark and repeat steps 2-4. 6. Move the pencil so that it is under the 40 cm mark and repeat steps 2-4. Fill in data table: No Lever 80 cm fulcrum 60 cm fulcrum 40 cm fulcrum Force (N) Force (N) Force (N) Force (N) 1 mass 2 masses 3 masses Using a lever changed the force’s (circle as many as apply)

size direction

distance

How does lifting the mass with no lever compare to lifting the masses with a lever? Where is the best place to put the fulcrum when the load is heavier? WHY? Station #3: Wedges Use the different objects at the station to press into the gravel. Using a wedge changed the force’s (circle as many as apply) size

direction

List the objects in order from most difficult to easiest to separate the gravel. What qualities made the objects easier or more difficult to separate the gravel?

distance

Station #4: Screws Take a piece of paper and cut into a right triangle. Draw a line along the hypotenuse. Tape the one of the legs of the triangle to the straw, then wrap the triangle around it, so that the you can see the line you drew along the hypotenuse wrapping around the straw. How is a screw related to an inclined plane? Using a screw changes the force’s (circle as many as apply) size

direction

distance

Read the section on screws on page 431. How does the threading of a screw relate to mechanical advantage? List at least one advantage and one disadvantage of screws with: smaller threading, larger threading. Station #5: Inclined plane Take a mass and lift it straight up with a spring scale. Record the force. Repeat lifting the mass to the same height, but use the ramp. Adjust the height of the ramp by changing the number of books supporting it. Force (N) No ramp 2 book ramp 4 book ramp 6 book ramp Using an inclined plane changed the force’s (circle as many as apply) size direction distance Station #6: Wheel and axle Push a book across the lab table. Do this again, but place two pencils underneath the book to act as axles. What do you notice? Using a wheel and axle changed the force’s (circle as many as apply) size direction distance How are wheels related to levers? Station #7: Computer Game Write down which simple machine was used and what you needed to do at each “level”.

Conclusion: On a separate sheet of paper, write a paragraph that a) states the purpose of these lab activities, b) has a sentence summary of each of the seven stations, and c) states what you learned about simple machines. Please staple the paper to this one.