2. A modem uses 94 W to operate , and its transformer,draws 16 W of power . What is its percent efficiency of the modem? (2. Percent efficiency =useful energy output times 100% (total energy Input)/(100% )

Here's how to calculate the percent efficiency of the modem:<br /><br />1. **Identify the useful energy output:** The useful energy output is the power used by the modem itself, which is 94 W.<br /><br />2. **Calculate the total energy input:** The total energy input is the power drawn by the transformer, which is 160 W.<br /><br />3. **Apply the efficiency formula:**<br /><br /> Percent efficiency = (useful energy output / total energy input) * 100%<br /><br /> Percent efficiency = (94 W / 160 W) * 100%<br /><br /> Percent efficiency = 0.5875 * 100%<br /><br /> Percent efficiency = 58.75%<br /><br />Therefore, the percent efficiency of the modem is $\boxed{58.75%}$.<br />