Question

The wattage rating of an appliance is given as W, in watts, and varies jointly as the resistance, R, in ohms, and as the square of the current, I, in amperes. If the wattage is 36 watts when the resistance is 100 ohms and the current is 0.6 amperes, find the wattage when the resistance is 300 ohms and the current is 0.5 amperes.

Answer 1

Hmm, if I'm understanding the set up correctly, you have the equation
\[W=I^2R\]

Answer 2

ok

Answer 3

Oh hold on, there should be an unknown factor we'll call \(k\):
\[W=kI^2R\]
So first off, you have to find \(k\). Given that \(W=36,~R=100,~I=0.6\), you can plug them all into the equation and solve for \(k\).

Answer 4

After that you solve for \(W\) given that \(R=300\) and \(I=0.5\) as well as whatever you find for \(k\).