The resistance R of wire varies directly as its length L and inversely as the square of its diameter d
a.write an equation that express this joint variation (use k for the constant proportionality)
B.find the constant of proportionality if a wire 1.8m long and 0.005m in diameter has a resistance of 190ohms (round your answer to six decimal places)k=?
a) The equation that expresses this joint variation is:
R = k * (L / d^2)
where R is the resistance, L is the length, d is the diameter, and k is the constant of proportionality.
b) To find the constant of proportionality, we can substitute the given values into the equation and solve for k:
190 = k * (1.8 / 0.005^2)
Rearranging and simplifying the equation:
k = 190 / (1.8 / 0.005^2)
k = 190 / (1.8 / 0.000025)
k = 190 / 72000
k ≈ 0.002638889
Therefore, the constant of proportionality (k) is approximately 0.002638889.
a. The equation that expresses the joint variation between the resistance R, length L, and diameter d of the wire is:
R = k(L / d^2)
b. To find the constant of proportionality, we can use the given information. Let's substitute the known values into the equation:
190 = k(1.8 / 0.005^2)
Simplifying:
190 = k(1.8 / 0.000025)
190 = k(72,000)
Now, divide both sides of the equation by 72,000:
k = 190 / 72,000
Simplifying this division gives:
k = 0.002638
Therefore, the constant of proportionality (k) is approximately 0.002638 (rounded to six decimal places).