Question 199143
Sailboat speed. The sail area-displacement ratio S provides
a measure of the sail power available to drive a boat.
: 
For a boat with a displacement of d pounds and a sail area of A square feet S
 is determined by the formula
:
S = {{{16A(d^(-2/3))}}}
:
a) Find S to the nearest tenth for the Tartan 4100, which
has a sail area of 810 square feet and a displacement of 23,245 pounds.
S = {{{16*810(23245^(-2/3))}}}
S = 12960 * .00122776
S = 15.9 knots
:
b) Write d in terms of A and S.
 {{{16A(d^(-2/3))}}} = S
:
{{{d^(-2/3)}}} = {{{S/(16A)}}}
:
d =  {{{(S/(16A))^(-3/2)}}}