Question

Why is it important to use the same amount of something when you do an experiment twice?
Give a scientific reason, not just "so ya don't mess it up."

Answer 1

not really.. depends on what you want

usually when u carry out physics experiment, you do each trial with different inputs.. so what exactly are u referring to?

Answer 2

Depending on what you're testing for.. Well the main reason for using the same amount each trial is because, if you use less or more than the original trial the outcome will be different. You have to keep it constant in order to make sure that the conclusion will be "The reason this substance worked better than this other one is because of its properties." and not "Well i think it worked better because i added more...Not because its a difference substance."
Get what I'm saying?

Answer 3

This applies more to chemistry.

Answer 4

ohw.. right chemistry

well.. cause for every reaction.. or atleast most of it.. u need a specific proportion of reactants.. if u don't, then either the reaction doesn't work , or u get something unpredicted.. and that's why you need to take specific amounts!..

Answer 5

^ Exactly! It would be unpredicted so you wouldn't be able to tell whether or not your hypothesis was correct since you cant say it was because of the type of "something" or the amount of the "something". You wouldn't really be able to know unless using the same amount.

Answer 6

well..actually you really don't have to take the same amount.. as long as u take the same proportion :P.. its just that. its EASIER.. to take the same amount.. reduces the work of calculating and predicting outcomes..

who wants to do more math right? so we do math once.. with a set of inputs.. and then throw calcs away .. :D

Answer 7

There you go! Thats a better way of putting it. Proportions.
But yea doing proportions would take much more work with math haha.

Answer 8

Thanks guys :)

Answer 9

No problem!