What is the efficiency of a wheel and axle that uses 500J of input work for an output of 400J?

To determine the efficiency of a machine, you can use the formula:

Efficiency (%) = (Output Work / Input Work) × 100

In this case, the input work is 500J and the output work is 400J. Plugging in these values gives:

Efficiency (%) = (400J / 500J) × 100

= 0.8 × 100

= 80%

This means the wheel and axle converts 80% of the input work into useful output work, indicating a relatively high efficiency for this type of simple machine. Efficiency measures how well a machine converts input energy into output energy, and in this scenario, the wheel and axle is performing effectively, as a significant portion of the input work is transformed into output work.