Question

1. what is the efficiency of a machine that requires a 100 j of input energy to do 35 j of useful work?

Explanation:

Step1: Recall the formula for efficiency

The efficiency (\(\eta\)) of a machine is given by the ratio of useful work output (\(W_{useful}\)) to the input energy (\(E_{input}\)), expressed as a percentage. The formula is \(\eta=\frac{W_{useful}}{E_{input}}\times100\%\)

Step2: Substitute the given values

We are given \(W_{useful} = 35\space J\) and \(E_{input}=100\space J\). Substituting these values into the formula, we get \(\eta=\frac{35}{100}\times 100\%\)

Step3: Calculate the efficiency

\(\frac{35}{100}\times100\% = 35\%\)

Answer:

The efficiency of the machine is \(35\%\)