Solve each of the following logarithmic equations.
1.The relationship between the surface area A cm^2 and the volume V cm^3
of a sphere can be represented by the following formula:
A=4.836V^n (where n is a constant)
Given that the area of a sphere is 1 000 cm^2 and its volume is2 974cm^3,
find the value of n by using logarithms,and give the answer correct to 3 signficant
figures
ANS:0.667
2.Accordind to a research of oceanography, for every metre that a diver goes
down,the light intensity will increase by 2.5%.How many metres should a diver
go such that
(a)the light intensity is one fourth of that at the water surface?
(b)the light intensity is 1%of that at the water surface?
(give the anwers correct to the nearest integer)
ANS:(a)55m
(b)182m
F.4 MATHS (log)
2010-03-07 12:52 am
回答 (2)
2010-03-08 2:33 am
✔ 最佳答案
1. A=4.836V^n1000=4.836*2974^n
LOG(1000/4.836)=n LOG 2974
n=0.667
2. (a) (1-2.5%)^n=1/4
97.5%^n=1/4
0.975^n=1/4
n LOG 0.975=LOG(1/4)
n=55(give the anwers correct to the nearest integer)
(b) (1-2.5%)^n=1%
97.5%^n=0.01
0.975^n=0.01
n LOG 0.975=LOG 0.01
n=182(give the anwers correct to the nearest integer)
參考: 自己
2010-03-07 5:56 am
a)
sub A=1000 V=2974
A=4.836V^n
1000=4.836(2974)^n
log (1000/4.836)=n log 2974
n=0.667
sub A=1000 V=2974
A=4.836V^n
1000=4.836(2974)^n
log (1000/4.836)=n log 2974
n=0.667
收錄日期: 2021-04-23 18:26:49
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