What variable must be controlled on this one????

Your friend has to plan an experiment for a science fair. He asks for your help. His topis is ';The Strongest Cloth for Backpacks.'; What variables must his experiment include? What variables must be controlled?





Thanks coz i need help! :)What variable must be controlled on this one????
Controlled variables: Weight inside backpack, environment (temperature, humidity), how new the cloth is (if it has been used before or not)





Independent variable: cloth typeWhat variable must be controlled on this one????
mass added, (temperature of room), same surface area, same stitching, same volume.... all should be controlled
The variables are the fabric and the weight put into the backpack (perhaps also the amount of time the weight was in the bag and the person or thing that picks up the backpack).


The time and the person should be controlled.
the variables for the simplest experiment would be the cloth, the weight, and the time.





the weight would be the constant or controlled


the time would be the dependent


the cloth would be your changing variable





all of the diff. clothes would have to use the same amount of weight or else the experiement would be faulty


the time it takes the cloth to break would change depending on the cloth you use.
Controlled definitly what you put inside the backpack...enviroment, size of backpack, amount of usage, things like that. Anything that doesnt include the fabric needs to be a controlled variable.