Friday, 16 August 2013

Class Scribe, Drums, fireflies, skateboard ramp and potato chips... Oh My!

Guest post by Mrs. Tolisano

Class started with housekeeping items, homework and a review of the last class, including nuclear bombs. What are kinetic energies involved? Are their chemical reactions involved?

Mr. Prophet showed several videos to demonstrate the change in energy:

Wind turbine
starting energy (where is it coming from?) --> Final energy
wind (kinetic) things we can see and feel easily --> kinetic of turbine --> electricity and some sound.

electrical potential --> electricity kinetic --> light, thermal & sound

A chemical reaction in the animal changed chemical --> light (bioluminescent) & probably thermal.

Chemical --> sound, light and thermal

Hitting a drum starts out with a kinetic energy of drum stick to kinetic of drumstick -->  elastic and kinetic of drum --> sound
(video effect of a drumset in slow motion)

Space Jump
gravitational energy --> kinetic energy


Next step on the agenda was the SkateBoard Simulation. 

What did we learn?
  • What happens to the total energy over time?
    energy remains the same - it remains constant
  • What happens to the potential and kinetic energy?
    The kinetic is highest, increased to a maximum and the potential is almost 0
  • What happens to the potential at the top of the ramp?
    Potential is high, kinetic changes into gravitational
  • What is the relationship between kinetic, potential and total energy of the skateboard system?
    Total energy= kinetic + potential
What if we add Track friction?
Kinetic energy becomes 0
What happens to the potential energy over time?
It decreases, almost to 0
What happens to the thermal energy over time?
It increases each time until it becomes the same as the total energy
What happens to the total energy over time?
It stays constant
What is the relationship between all of them?
Total= Potential + Thermal + Kinetic

Moving on to the Investigation...

  • Tie back long hair
  • Do not sit
  • Wear googles throughout the whole investigation

Step 1: Weigh the potato chip

 Step 2: Measure 10 ml of water for the test tube

Step 3: Light a match and the alcohol

Step 4: Burn the chip with the fire

Step5: Thermometer goes in the water. Record temperature of water (initial)

Step 6: Hold burning chip under test tube with thermometer in it

Step7: Measure and record the temperature of the water after the entire chip burned.

Summary of Main Ideas:
  • Energy changes are all around us!
  • Anytime there is a change, we can analyze it in terms of energy.
  • In the investigation, when the chip/biscuit were burned, the chemical energy --> thermal of air --> thermal of test tube and water.  This changed the temperature of the water.

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