Posts tagged simple machines
Students leveraged some serious knowledge in order to be successful today. We took a look at the 3 components of a lever – fulcrum, load and effort.
We built levers out of rulers and then tested at specific fulcrum points to find out how many nails (effort) would need to be in a cup in order to move a fixed load. Results were recorded in a table and then students hypothesized about why the fulcrum affected the effort required.
This was our final day of simple machines. We’ll need the skills we’ve acquired to conquer upcoming challenges – next stop Mars!
STEM students spent a day with pulleys and learned how this simple machine can be used to change the direction of force applied.
For the grande finale, 17 students created a mega-chain of pulleys! We manipulated a single 100-foot rope through bookshelves, under tables, around corners, and from the ceiling to the supply closet. No one touched the rope except the initiator – everyone else simply held a pulley at the correct angle.
Our study of simple machines continued this week with a couple of experiments examining the wheel involved in a wheel and axle.
Vocabulary terms this week were circumference, diameter and radius. We completed measurements and made educated guesses about the relationship of radius and circumference, as well as of circumference and distance traveled per rotation. To see concepts in action, we went over to our middle school community friends at Nothwest CrossFit – where they have a giant tire that looks like it came off a fire truck or monster truck. Their tire has a circumference of 14 feet! Which definitely illustrated the ideas we discussed.
Our final exercise consisted of estimating how many tire rotations Tom’s bike would go through to get from the CrossFit gym back to school. Guesses ranged from 70 up to 250. As we walked, students altered their hypothesis in light of information gathered. Official answer: 204 rotations! Knowing that Tom’s tire was 6′ 9″, that means we walked 1377 feet.
6th grade students, cameras in hand, went in search of inclined planes on Friday as part of our STEM celebration of simple machines, some results are shown below. We also took some time to compare time trials from last week’s matchbox car races and graph the data. Our results didn’t quite match our hypothesis, but there are a number of variables that got in the way of perfect data – the human factor had an impact on the stopwatch, angle support and the dropping of the car.
6th grade students spent Friday deepening their understanding of inclined planes, one of the simple machines introduced last class. We jumped into two experiments that illustrated an inclined plane’s effect on speed, distance, time and effort.
Experiment #1: Wall v. Ramp!
Students had two backpacks loaded with books and were asked to raise them 8 feet and 3 inches. The first attempt required lifting the bag straight up a wall from the roof of the school! Though the bag didn’t have far to travel, it was really difficult to lift and required 3-4 students to manage the job. The second attempt involved using the ramp from the teacher lounge to the art studio. Students calculated the ramp to be 33 ft long, raising the bag 8’3″ vertically. Students computed the angle of the ramp to be approximately 13 degrees using a giant protractor. The ramp was much easier to pull books up, but there was more distance required.
Experiment #2: Race Cars!
Students used a lunch table, stop watch and protractor to capture the amount of time required for a matchbox car to travel from one end of a ramp to the other. They recorded 3 trials each for angles of 10 degrees, 20, degrees, 30 degrees, etc all the way up to 90 degrees. After isolating the median speed for each angle, we noted a correlation that was consistent with our initial hypothesis: the steeper the angle, the faster the car went and the less time it took for the car to reach the bottom.
How can you move a teacher from one end of a room to another without hurting yourself?
How can you get bigfoot to slide off a filing cabinet into a pool of water without touching any part of the apparatus?
How can a teacher be stronger than 4 students in a game of tug-of-war?
How can a 6th grade student lift an entire school bus?
6th grade STEM kicked off the year with an introduction to the wheel & axle, inclined plane, pulleys, and levers – simple machines that we use to create mechanical advantages and perform amazing feats. Student groups rotated through 4 stations, each introducing a concept, and then put their knowledge into action.
Groups also learned how artists, archeologists, stuntmen & women, and baseball players use science, technology, engineering and math to excel in their careers.
A great start to the year – stay tuned for more exciting news from the lab…