Acceleration and the measurement of acceleration

Subject:  Physics

Date:

Teacher:

 

 Title:  Estimating force

Central Concept:  Understanding the realtionship between force and motion

Learning Standards (National Science Education Content Standards):

B.4 - Motion 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:

What is Newton's second law?

What is force and what is its effects on a mass?

What is the relationship between acceleration and position?

How can we measure the change in position of something that happens very rapidly?

 

Content and Skills:

Develop a mathematical understanding of the realtionship between force and acceleration (B.4)

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

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

 Learning Activities:

  • Discuss concepts related to force: How is motion and force related?  Does force always result in motion?...
  • Introduce Newton's second law.
  • Go through an example problem on the board.  Something simple:  What force is required to accelerated 1500 kg at 3 m/s/s?
  • Discuss force units.
  • Show video of lizard jumping. Is the lizard moving?
    • Look at this motion graph - can we see from it when the lizard applies the force with its legs?
  • Group Activity: Lets calculate the force exerted by the lizard in order to propel it forward:
    • Separate students into groups and begin disussion:  How can we estimate the force?  Do we have enough information?
    • Ask groups for solutions:  What additional information is required to calculate the force exerted by the lizard?
      • The mass of the lizard is approximately 4 grams or 0.004 kg.  Do we now have enough information?
    • Work through the problem with the students - assess students' understanding of material

Equipment / Materials:

Internet access – projector or computer lab

Expected Outcomes:

Students should:

  1. Understand the relationship between force and acceleration
  2. Understand how to graph and use data plots to solve problems
  3. Understand force units

Assessment / Assignment(s):

Homework:

Using the data from the previous homework assignments where velocity and acceleration were calculated, determine the maximum force exerted by the lizard.