To make an experiment fairly tested you need to keep the surface the same and the way you do the experiment the same. Reply ↓
To carry out a fair test you have to make every thing the same but not the object.
friction can be useful because it stops things from slipping or moving
To make an experiment fairly tested you need to keep the surface the same and the way you do the experiment the same.
Friction can be used as grip for when your hiking.