Joint Variation.
The weight of a cylindrical metal varies jointly as its length L and the square of the diameter d of its base.
a. If Wis equal to 6kg. When L = 6cm and d=3cm, find the equation of variation.
b. Find L when W is equal to 10kg and d=2cm
c. Find W when d=6cm and L=1.4cm

pLS. HELP me . thank u

1

Answers

2014-10-07T23:12:59+08:00
The equation is
W = k L d²            where k = constant
                                       L = length
                                       d = diameter 
6 = k 6 .  3²
k =      6/6 .9  =    1/9
10 = 1/9 L 2²  =  L 4/9               /just plug in the values
 L   =    10 . 9/4= 22.5cm
W  =   1/9 . 1.4 . 6²
     ~ 5.59 kg
in these kind of problems you must always
find the constant first








      

                  
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