Depends on the goal of the experiment. If the only aim is to determine the sqishability of the butter, then a plastic bag would be acceptable as it would provide no meaningful resistance to the tire. However, if one wishes to determine the precise nature of the butter’s squish, then many more experiments need to be made, both to establish a control and to analyze additional squish conditions (butter temperature, wrapper on/ off, use of plastic bag, etc.)
I dunno, plastic bags sound like confounding variables. The 4 year old peer reviewers won’t stand for this!
Depends on the goal of the experiment. If the only aim is to determine the sqishability of the butter, then a plastic bag would be acceptable as it would provide no meaningful resistance to the tire. However, if one wishes to determine the precise nature of the butter’s squish, then many more experiments need to be made, both to establish a control and to analyze additional squish conditions (butter temperature, wrapper on/ off, use of plastic bag, etc.)
The question was what happens when you run over a stick of butter, not how squishable is a stick of butter