The volume of a spherical balloon varies directly as the cube of its radius.
a) If the radius of the spherical balloon is increased by 5%, find the percentage
increase in the volume
Ans: 15.8%
b) If the volume of the spherical balloon is decreased by 20%, find the percentage decrease in the radius.
( Give the answers correct to 3 significant figures.)
SS1 Maths Direct Variation
2010-05-22 7:52 pm
回答 (1)
2010-05-22 8:23 pm
✔ 最佳答案
a)V=kr^3, where k is a constant
V'=k[(1+5%)r]^3=k(1.05r)^3=1.158kr^3=1.158V
Percentage increased=(V'-V)/V*100%=15.8%
b)
V'=(1-20%)V=0.8V
k(r')^3=0.8*kr^3
(r')^3=0.8r^3
r'=0.9283r
Percentage decreased=(r-r')/r*100%=7.17%
收錄日期: 2021-04-22 00:49:48
原文連結 [永久失效]:
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