Thanks for your feedback! The concepts of stability and equilibrium are introduced while students learn how these ideas are related to the concept of center of mass. They gain further understanding when they see, first-hand, how equilibrium is closely related to an object's center of mass. So that bridges and buildings will not fall down, and roller coasters and parachutes work, engineers and designers must understand the concepts of balance and equilibrium.
You might be interested in balance, too, if you like to ride a bike, move around or even sit in a chair! Like people, structures that engineers design need to be able to keep their balance when something pushes on them, such as wind, or the weight of people, snow or cars. Sometimes things can balance themselves; think of the inflatable toy called a "bop bag" that stands back up after being punched. Engineers say that objects that can rebalance themselves are in stable equilibrium.
Other objects are unable to rebalance themselves; if you push them out of balance, they fall over. Engineers say that things that cannot rebalance themselves are in unstable equilibrium. Engineers who design things that balance — such as a skyscraper, a house or a bridge — must make sure that the objects are in stable equilibrium. If engineers did not do this, buildings and bridges might fall over when they were pushed by even a gust of wind!
Understanding stable equilibrium is important for our day-to-day safety. In this activity, you will explore equilibrium and learn about stability. You will learn about what characteristics affect whether our paper cut-out parrot sitting on a wire is in stable or unstable equilibrium! Brainstorming: Have the students engage in open discussion, creating a class list of real-life items that need to consider balance to work properly.
Concept Reflection: Have a few students describe a situation in which something was off-balance or in unstable equilibrium. Pairs Check: After student groups have completed balancing Polly the Parrot on her perch, have them compare strategies with other classmates, giving time for all groups to balance their parrots. Journal Reflection: Ask the students to write a paragraph, in their science journal or on a sheet of paper, to explain what happened to Polly when they tried to knock her off her perch and why it happened, in terms of the concept of center of mass.
Activity Discussion: Review and discuss the activity with the entire class. Use the answers to gauge students' mastery of the subject. If time permits, complete the Activity Extension. If the parrot does not balance right away when placed on its perch, advise the students to compensate by either adding paper clips to its tail or by trimming the tail, depending on which way the parrot is tipping off balance.
Have students experiment with their body's center of mass! In the classroom, push a chair against a wall and ask a student to sit in it. Then put your finger on the student's forehead and ask them to stand up. Have them explain why they cannot stand up, in terms of the concept of center of mass.
Next, place a chair sideways against a wall. Have a student stand outside of the chair and bend at the waist until their forehead touches the wall over the chair. Then ask the student to pick up the chair and stand up. Why can girls do it and not boys? Have the students explain in terms of center of mass. Finally, conduct the same chair activities again, but have the person wear a backpack full of books. Have the students explain the results, in terms of their center of mass. Hauser, Jill Frankel.
Its center of mass or center of gravity is generally beneath the tip of its beak. Our proud bird can even be used to demonstrate rotational inertia! Just balance it on a pencil above your head, and turn around degrees. The bird will remain in the same orientation due to its fairly large moment of inertia.
The toy gyroscope has been in production since and has been a classic educational tool for generations. Use the power of physics to balance the gyroscope on its pedestal, a fingertip, the edge of a glass, or even a string.
Gyroscopes are used in robotics, space exploration, and they are even used to stabilize movie cameras. Each gyroscope is packed in a clear styrene box with starting string, pedestal, and instructions for several amazing tricks. Measures 4. When spun, it starts out horizontal and then, surprisingly, stands upright. In the process, it illustrates the difference between equilibrium and stability. It will spin for minutes on end, producing a marvelous optical illusion as it slows down.
Invented by astrophysicist Kenneth Brecher, the PhiTOP encourages exploration of force, mass, density, gravity, friction, and time. In short, the PhiTOP is an elegant scientific, mathematical, and aesthetically-pleasing object that makes a perfect gift, desktop display piece, or student stumper. See for yourself in our video! Bring a refrigerator magnet next to a PhiTOP that is made from a non-magnetic metal such as aluminum or brass while it is spinning and it will slow down and stop.
The original 19th century apparatus employed a rotating 3-phase magnetic field configuration with no moving parts to spin up a copper egg shaped object. This entry was posted on Friday, May 27th, at am and is filed under Elementary level , experiments , Middle School level , Physics. You can follow any responses to this entry through the RSS 2. You can leave a response , or trackback from your own site. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment.
Notify me of follow-up comments by email. Notify me of new posts by email. This site uses Akismet to reduce spam.
Learn how your comment data is processed. Sign up now. Theme: Contempt by Vault9. Get a free blog at WordPress. My Account.
0コメント