Jaws as Levers

 

Subject: Physics

Date:

Teacher:

 

 

Title:  Levers: forces and motions

Central Concept:  Understanding the relationship between force and range of motion in levers

Learning Standards (National Science Education Content Standards):

B.4 - Motions and forces

A.1.4 - Formulate and revise scientific explanations and models using logic and evidence

A.1.1 - Identify questions and concepts that guide scientific investigations

 

Essential Questions:

How do levers work?

How to model real world structures are simple lever mechanisms?

What is the relationship between force and range of motion of a lever?

Content and Skills:

Develop a mathematical understanding of acceleration(B.4)

Understand methods for taking measurements of acceleration(B.4)

Scientific inquiry and reading comprehension (A.1.4, A.1.1)

Learning Activities:

  • Discuss levers - what are students' understanding of how levers work? What are levers used for?
    • Introduce students to the levers and the different classes of levers
    • What types of devices use levers? ex: pliers, wheelbarrow, fishing rod.
    • Why would one chose one type of lever over another? Is there an advantage in force or motion?
    • Introduce the equations for class 1, 2, and 3 levers
  • Can we model parts of animal or human anatomy as levers? Draw on the board diagrams of the types of levers one might see in a human body.
  • Lets look at alligators and gharials:
    • What is a gharial? Show photo
    • Are gharials very different from alligators? Show Photo
    • Show side by side comparison. Photo
    • Why would their jaws look this different? Different food means different jaws. Gharials exclusively eat fish, while alligators eat larger and stronger prey.
    • Discuss speed and force advantages brought upon by the different jaw geometries.
    • Prepare the students for their homework by showing a quick example of lever advantage on the board

Equipment / Materials:

Internet access – projector or computer lab

Expected Outcomes:

Students should:

  1. Understand the different classes of levers and what are their uses
  2. Understand the relationship between range of motion and force in levers
  3. Understand how to model a jaw as a lever

 

Assessment / Assignment(s):

Homework:

Give students the web link to the gharial/crocodile page where they will find a homework problem.