(3)
某同學(xué)通過以上數(shù)據(jù)測(cè)得重力加速度的大小為
, 若當(dāng)?shù)氐闹亓铀俣戎禐?img class="mathml" src="http://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E9%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E8%3C%2Fmn%3E%3Cmi%3Em%3C%2Fmi%3E%3Cmn%3E%2F%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3Es%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3C%2Fmath%3E" style="max-width:100%;vertical-align: middle;"> , 請(qǐng)寫出產(chǎn)生誤差的主要原因