UTPA STEM/CBI Courses/Physics (General)/Work & Energy

Course Title: Physical Science I

Lecture Topic: Work & Energy

Instructor: Mr. Mario A. Lopez

Institution: South Texas College, Starr County Campus

Backwards Design

Course Objectives

• Primary Objectives- By the next class period students will be able to:
  • Describe and find the benefits and applications of work and energy, forms of energy, and conservation of energy (including work-energy theorem).

• Sub Objectives- The objectives will require that students be able to:
  • Define work and energy, and conceptually understand how they are related.
  • Recognize the work-energy theorem; that is, Work = ΔKE.

• Difficulties- Students may have difficulty:
  • Performing simple algebra
  • Remembering rules of arithmetic
  • Comparing like terms
    • Checking for like units (m, m/s, m/s2, N, J, etc.)
    • Understanding fractions and decimals and their relationships
    • Conceptualizing the difference between speed and acceleration and that acceleration is a process requiring time.

• Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
  • Investigating automobile accidents

Model of Knowledge

• Concept Map

• Content Priorities
  • Enduring Understanding
    • Work, Energy, KE, PE, time, mass, distance, motion, force, velocity, acceleration, heat, friction, weight
  • Important to Do and Know
    • Simple Math
    • Simple Formulas
    • Comparison of like terms (less than, greater than)
  • Worth Being Familiar with
    • Units of measure
    • Conversion factors between units
    • Scientific notation

Assessment of Learning

• Formative Assessment
  • In Class (groups)
    • Problem solving using energy conservation and work-energy theorem (groups).

• Summative Assessment
  • Students report their findings.

Legacy Cycle

OBJECTIVE

By the next class period, students will be able to:

• Describe and find the benefits and applications of work and energy, forms of energy, and conservation of energy (including work-energy theorem).

The objectives will require that students be able to:

• Apply the formula for the work energy theorem (Work = ΔKE) to solve very simple physics problems.
• Identify other formulas, including Work = Fd and KE = (¹/₂)mv².
• Use simple algebra to manipulate equations.
• Perform simple arithmetic using a calculator.
• Use conversion factors to convert between units.
• Produce scatter plots with one independent and one dependent variable.

THE CHALLENGE

While driving along a residential street with a 25 mph speed limit, the distracted driver of a Ford F-150 crashes into the rear end of a parked Chevrolet Metro. The Metro is pushed forward 10 feet in the collision. Afterwards, the F-150 driver’s insurance company wants to know whether their customer violated the speed limit at the time of the collision. You work for an engineering consulting firm hired by the insurance company. Your job is to determine the Ford F-150’s speed at the moment of impact.

GENERATE IDEAS

How can the work-energy theorem be used to determine the speed of a moving vehicle at the moment that it crashes?

MULTIPLE PERSPECTIVES

Students watch video of elastic and inelastic collisions to help recognize assumptions that may need to be made.

RESEARCH & REVISE

Instructor briefly lectures about assumptions that will be used for some of the terms involved in the work-energy theorem. Students use library and internet resources to find weight and coefficient of friction for the vehicles involved in the traffic accident presented in the Challenge.

TEST YOUR METTLE

Students solve simple problems involving the work energy theorem while doing a lab exercise to discover the relationship between KE and stopping distance.

GO PUBLIC

Students present their answer to the challenge to the class.