If a machine has an efficiency of 80% and it consumes 1000 J of energy, what is

If a machine has an efficiency of 80% and it consumes 1000 J of energy, what is the useful work output?

If a machine has an efficiency of 80% and it consumes 1000 J of energy, what is the useful work output?

Correct Answer: 800 J

Step 1: Understand the problem. We need to find out how much useful work a machine can do when it consumes a certain amount of energy.
Step 2: Identify the efficiency of the machine. In this case, the efficiency is 80%. This means the machine can use 80% of the energy it consumes to do useful work.
Step 3: Convert the efficiency percentage into a decimal. To do this, divide 80 by 100. So, 80% becomes 0.8.
Step 4: Identify the input energy. The machine consumes 1000 J of energy.
Step 5: Use the formula for useful work output: Useful Work = Efficiency * Input Energy.
Step 6: Plug in the values into the formula. Useful Work = 0.8 * 1000 J.
Step 7: Calculate the useful work output. 0.8 * 1000 J = 800 J.
Step 8: Conclude that the useful work output of the machine is 800 J.

Efficiency – Efficiency is the ratio of useful work output to the total energy input, expressed as a percentage.
Work Output Calculation – The useful work output can be calculated by multiplying the efficiency (as a decimal) by the total energy input.