Topic: Levers in the Human Body
Entire Activity Download (16 pages)
lever, fulcrum, effort, resistance, class, force
Classes of levers, Forces at work in each class of lever
Process Skills Utilized
Observing, Inferring, Measuring
Intended Grade Level - 6-8
By setting up levers and measuring forces, students will be able to:
Name and define the parts of a lever
Describe the location of the fulcrum, effort and resistance in each class of lever
Investigate the forces involved in each class of lever
Draw conclusions regarding appropriate application of each class of lever
Students will explore the parts of a lever and will build a model of each class of lever on a wooden stand using dowels and modified wooden rulers. Using a spring scale and hanging weights, students will study the forces and will determine the advantage of each type of lever. As a grand finale to the activity, students will apply their newly found knowledge of levers as they compete in a contest called the “Little Bit of Effort Contest.” Students will work in their groups to design the most efficient lever in each class, ie the lever that can move the most weight with the least amount of effort.
Activity Materials (per group)
Copy of Student Background Information Packet
1 Copy of Student Data Page Packet per student
Wooden stand with hook inserted
3 Binder clips 1 1/4” wide, 5/8” capacity
Hanging weight set
Spring scale – measurement scale needs to match that of hanging weight set
Certificates for “Little Bit of Effort” Contest
Activity Management Suggestions
Students should work in groups of two to four. Remind students to use good time management skills and to divide the jobs equally so every member of the group has a fair share of the tasks. During the “processing out” time, be sure that students have discovered the unexpected result related to third class levers. Students expect to find that each lever will reduce the amount of force needed to move an object and will be surprised to find that the third class lever actually has a mechanical disadvantage. This concept will be important for students as they progress to the next activity on biomechanics of levers in the human body.
Students can collect household tools and determine which type of lever they represent.
Activity References Used
Broer, MR. (1973) Efficiency of human movement (Third Edition). Philadelphia: W.B. Saunders Company.
Gowitzke, BA & Milner, M. (1988). Scientific bases of human movement (Third Edition). Baltimore: Williams & Wilkins.
Gray, H. (1918). Anatomy of the human body (20th Edition). Philadelphia: Lea & Febiger.
Hamill, J. & Knutzen, KM. (2003). Biomechanical basis of human movement (Second Edition). New York: Lippincott Williams & Wilkins.