Posted by David R. Wetzel, Ph.D.
Cola or Water?
One way to peak the interest of your students is to conduct an experiment using objects of things that they encounter often or even on a daily basis.
This investigation is designed to determine if plants prefer cola or water to grow.
An Inquiry Investigation
- 2 small plant pots with saucers
- paper for data collection
- Place each plant in a small plant pot
- Label one pot – water
- label the other pot – cola
- Add water to the pot labeled water until the soil is moist
- Add cola to the pot labeled cola until the soil is most
- Take pictures of both pots
- Measure and record the height of the both plants, along with any other observations made of the two plants
- Make daily observations of the plants for 5 days, record observations and take pictures
- Ensure the soil in both plants remains slight moist throughout the investigation
Answer the following questions:
- Write a short story describing all observations and what happened to both plants.
- Which plant was surviving after 5 days?
- Why was the plant that was not surviving, dying?
- What would happen if diet cola was used instead of cola?
- What would happen if another type of carbonated drink were used instead of cola?
- How could the investigation be redesigned to test if plants like cola or water? (hydroponics is one alternative)
Students will find that acidic level of cola, along with the other ingredients in cola, will kill the plant only given cola.
20 Questions to Ask Students in Science
Problem Solving and Science Process Skills
Effects of Acid Rain on Plants
Posted by David R. Wetzel, Ph.D.
Solar Energy Transformation
Simple demonstrations of solar to energy transformations allow students to investigate energy transformations into other types of energy. Examples include: solar to heat, solar to electrical, chemical to electrical to mechanical, mechanical to electrical to heat, etc.
The following investigation is safe for students to study energy transformations.
Solar to Electrical to Heat Energy Transformations
The image demonstrates solar energy being transformed into electrical energy (solar panels). The electrical energy is then transformed to heat energy as it heats the water in the tank (red color in in tank indicates cold water transformed to hot water by electrical heating strips in the bottom of the tank).
This can be investigated in the classroom by doing the following:
Small solar panel, thermometer, small beaker or clear cup, water, and 1.5 feet of non-insulted wire, bright flashlight (if do not have access to sunny window)
Hold a class discussion about energy transformations: however, do not focus specifically on the transformations in this investigation. The discussion needs to be on all types of energy transformations, allowing the students to guide the discussion and share what they know in advance from prior knowledge and experiences (PKE).
- Fill beaker half full of water
- Measure the temperature of the water with the thermometer and leave thermometer in water
- Connect each end of the non-insulated wire to the solar panel
- Coil the looped end of the non-insulated wire four times and place into water
- Shine bright flashlight (or sun light) on solar panel
- Record the temperature of the water over a period of several minutes
Sample Questions to Ask Students -
- Ask students to explain what happened and evidence to support their explanation.
- What type of energy transformations occurred and their evidence to support their answer.
- Ask students how or where their findings in this investigation influenced by their PKE.
- Ask students to explain any examples of potential and/or kinetic energy.
- Students form a hypothesis based on PKE.
- Students measure time of temperature changes with a stop watch.
- Students draw a graph of the temperature changes – indicating independent and dependent variables.
- Students explain control and uncontrolled variables.
The following resources can be used to support this investigation:
Understanding Scientific Inquiry
20 Questions to Ask Students in Science Projects
Writing in Science
FT Exploring Energy Transformations