In this experiment you will test the stability of a stack of blocks as the angle of the surface, the stack rests on gradually Increases. Using a fishing sinker tied to the center of mass, you will be able to see the posmon of the center of mass relative to the base of the object as It begins to tip over.
Materials
1 Fishing Sinker ………………….4 Wooden Blocks
Protractor ………………………*1 Empty Water Bottle with Lid
30 cm. String ………………….*Water
Masking Tape
Ramp Runway
Ruler …………………………..‘You Must Provide
Procedure
Part 1
1. Mark the location of the center of gravity on one side of a wooden block with a piece of masking tape [the middle}.
2. Using masking tape, attach one block above and below your original so that your center of gravity mark is visible, making a 3-btookhigh tower.
3. Use a ruler to measure and cut 30 cm. of string. Tape the string to the mark on the middle block with 20 cm hanging downward.
4. Attach a sinker to the end of the string. Set the block stack on top of the ramp, and line the edge of the ramp runway up with the edge of a table so that the strung can dangle.
5. Increase the incline of the ramp runway, and notice the relationship between when the block stack starts to tip over and the location of the string. Record your observation in Table 1.
6. Try this out with [out blocks stacked. Make sure to move your center of mass to the middle of the tower (between the second and third blocks). Record your observations In Table l.
Part 2
1. fill one of the water bottle one fourth fun of water.
2. Stand the bottle upright on a table. Slowly tilt the bottle by pushing the top of one side with one hand while supporting the opposite side of the bottle with a finger form your other hand.
3. Push the top of the bottle further and further checking every once m a Mule to see If the bottle will fall back upright it you were to stop pushing.
4. Continue pushing the top of the bottle up until an angle where the bottle will not tip beck uptight and support that angle with the finger form your other hand.
5. Use the protractor to measure the angle between the side of the bottle your finger is supporting and the table. Record the angle In Table 2.
6. Repeat Steps 2 – S with the bottle half full, three fourths full and completely full.
Record your angles In Table 2.
Post-Lab Questions
1. When did the blocks typically fall met?
2. Which stack of blocks (3 or 4) had a lower center of mass? Which sot tipped met at the largest angle? How do you know?
3. If you were building a skyscraper in a windy City, where would you want most of the building’s weight to be located?
4. Draw a rough diagram for each case showing the placement of the center of mass (point CM) and the maximum angle of the bottle reached.
5. Explain why you were able to tilt the bottle more in some cases more than others.
6. How soon do you think the bottle would tip over if you could fill only the top half?
