What are variables (independent, dependent, and controlled)?
I have to do this experiment for science. the experiment is for the greenhouse effect. the experiment: 1)Take two identical glass jars each containing 2 cups of cold water. 2)Add 5 ice cubes to each jar.3)Wrap one in a plastic bag (this is the greenhouse glass).4)Leave both jars in the sun for one hour.5)Measure the temperature of the water in each jar.
the teacher wants me to clearly state all variables (independant, dependent, and controlled) and i was wondering wat the variables for this experiment were.
Olivia - great name! My 5-year-old granddaughter is Olivia.
Since Olivia's are near and dear to my heart, I'm going to let you in on a little secret. The jar itself, never mind the plastic bag, is a greenhouse. Also, the ice cube will melt pretty quickly, plastic bag or not. After an hour both ice cubes will have melted and you still won't know very much.
If I were designing an experiment to model the greenhouse effect I would take two thermometers attached to a pieces of constructon paper of the same size and color. Place one thermometer and paper in a fish bowl or large bottle and leave the other one in the open. Be sure the fish bowl or bottle is closed. Then monitor the temperature over a period of time. I would predict that the unenclosed thermometer will indicate the ambient air temperature, but the one in the container will be considerably higher. There's your greenhouse effect.
The variable is the enclosure. Other variables include the thermometer and the surface the thermometer is on, as well as the lightsource (sunlight) and the time the thermometers are exposed to the sunlight. The whole idea of an experiment is to vary one variable at a time -- that would be the enclosure -- while keeping the other variables constant.
Good luck. Email me if you need any more help. Just click on the link to pisgahchemist.