Question 3 please help

Which experiment would most likely contain experimental bias

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home.what is displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

Linda and julia are trying to determine whether their ideas are scientific or pseudoscientific. linda's idea is free of bias. julia's idea gives the same result when tested repeatedly. which statement is correct about linda and julia's idea?