Question 1083857
the direct variation formula is y = k * x


the indirect variation formula is y = k / x


the combined direct and indirect variation formula is z = k * x / y


replace z with R and replace x with L and replace Y with D^2 and the formula becomes:



R = k * L / D^2


R is equal to 1.2 when L is 240 and d is 1.


formula becomes 1.2 = k * 240 / 1^2


solve for k to get k = 1.2 * 1^2 / 240 = 1.2 / 240 = .005


that's the value of k which is the constant of variation.


it remains the same regardless of the values of R or D or L.


when d = 3 and L = 610, and k = .005, the formula becomes R = .005 * 610 / 3^2.


this results in R = .3389 ohms.