Wednesday, October 25, 2017

The Speed of Falling Objects - and Other Experiments for the Classroom

The following classroom activities are engaging and deal with HS-PS2 Motion and Stability: Forces and Interactions.
The Chart Can be Found at HS-PS2 Motion and Stability

According to the NGSS the performance expectations for "Disciplinary Core Ideas for PS2 were developed by using - in part:
  • Structure and Properties of Matter:
    •  Matter at the bulk scale are determined by electrical forces between and within the atoms.
  • Forces and Motion
    • Newton's second law accurately predicts changes in the motion of macroscopic objects
    • Momentum is defined for a particular frame of reference: it is the mass times velocity.
    • If a system interacts with objects outside of itself the total system can change - however any change is balanced in the momentum of objects outside of the system. The Next Generation Science Browser has information and engaging lessons to highlight PS2.2 at the high school level.
  • Types of Interactions: 
    • Newton's law of universal gravitation and Coulomb's law provide the mathematical models and predict the effects of gravitational and electrostatic forces between distant object. (Because objects have mass they are attracted to each other and this is a difficult concept for some students to grasp). (HS-PS2-4) and (HS-PS2-5)
    • Attraction and repulsion between electric charges at the atomic scale explain the structure, properties and transformation of matter, as well as the contact forces between material objects. HS-PS-2-6, secondary to HS-PS-2-1, secondary to HS-PS1-3)
  • PS3.A: Definitions of Energy
    • "Electrical Energy" may mean energy stored in a battery or energy transmitted by electric currents (secondary to HS-PS2-5)
  • ETS1.C: Optimizing the design solution
    • Criteria may need to be broken down into simpler ones that can be attached systematically and decisions about the priority of certain criteria over others (trade-offs) may be needed. (secondary to HS-PS2-3)

Analyzing and Interpreting Data

Analyzing data in 9–12 builds on K–8 and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data. Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims or determine an optimal design solution.

HS-PS-2-1: Analyze data to support the claim that Newton's second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass and its acceleration.

My NASA DATA has top tear NGSS lessons that support the initial phases of Analyzing and Interpreting Data Content for grades K-12.

The Indianapolis Pubic Library "Kids' Blog" has a wonderful collection of lessons including "Science Experiment: Newton's Second Law of Motion". This is a fun lessons for any age students called "Comet Cratering Experiment and it proves that pulling or pushing an object produces acceleration, a change in the speed of motion. The heavier the object the more force it takes to speed up or slow down an object.

Physics for Kids is a great website to explain Newton's Second Law of Motion. The site offers links to other lessons and examples of Newton's Second Law of Motion - Change in motion is proportional to and in the same direction as, the applied forces.

Lesson ideas:

  • Chair
  • Electric fan
  • paper
Goals: To understand the concepts of force and work. To understand that objects move in the same direction as the force that acts upon them.

  • Begin with having a few students push against the wall and ask -- Everyone think for a moment - what are they doing? (Don't correct possible answers yet).
  • Ask another group of students to pull something that will not move - counter, dry erase tray - anything and ask -- Everything think for a moment - what are they doing?
  • Derive at "push" and "pull" and then ask: What do we call a push or a pull?
    • Lead students to "force"

Important!!! Tell students:

  • A FORCE is any push or pull.
Ask a student to sit in a chair and pull him or her across the room.

  • SAY: What are you observing?
    • You are looking for exerting a force

Important!!! Tell students:

  • To exert is to put into action. Give the term exert if they don't get to it.
  • SAY: How does this force compare to the forces we exerted on the wall.
  • SAY: What is the combination of force and movement? 
  • SAY: Work is the is the combination of force and movement

Push the student again.

  • Ask: What am I doing
Answer should be: exerting a force. Doing work.  

Move the student in multiple directions and explain about the direction of forces and the direction of movement - that objects move in the same direction as the force on them.

PUT the electric fan front and center.
BREAK students up into groups.
HAND OUT newspaper.

Have students wear their hats and stand in front of the fan OR hold the fan up and blow their hats off.

Have students work their experiment on the notebook pages in their science journal.

The student Science Journal may be purchased at the link for $6.00 plus shipping. It may be downloaded at www. - or a set of 32 may be ordered for $100.00 plus shipping of $16.00 by emailing


Just for fun: Be a Famous Perfume Maker (aka Chemist)

Things you need to know:

  • Alcohol (the rubbing kind) makes a great solvent for dissolving fragrant oils found in flowers, herbs, fruit and the like.
  1. Get a clear glass or plastic container with a lid - the prettier the better - or one of those small mason jars that are oh so popular. You'll need one per student.
  2. Have students go on a gathering field trip at home. Tell them they are going to make perfume and they get to pick the scent.
  3. Brainstorm ideas:
    1. cloves
    2. lemon peel (explain zest)
    3. orange peel
    4. flowers
    5. herbs
    6. cinnamon
    7. roses
    8. Any flower pedels
    9. ANYTHING  - who knows - they may create the next Obsession.
  4. Have students put their ingredients into their containers and cover with about 4 tablespoons of rubbing alcohol.
  5. Shake twice a day for one week.
  6. At the end of the week it is ready - dab a little on and see what they think.
  1. Have students create a label for their perfume and a brand
  2. Have students make commercials or print ads
  3. Have a contest to decide who likes which scent.
Then tell them: It takes about 8,000 to 10,000 crushes roses to make one dab (barely an oz) of rose oil for perfume, but that chemists have found a way to capture the flowers fragrance. They analyze the rose molecules and make the scent by artificially reproducing the natural oils.

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