Question

efficiency is the ratio of work input to work output. it is expressed as a percentage (%). the higher the percentage (%) is, the higher the efficiency of the machine. work input is the amount of work put into a machine. work output is the amount of work done by the machine. friction is the force opposing motion when two objects are touching. choose the correct answer what is work output? the amount of work put into a machine. the amount of work done by the machine. the opposing force one object exerts on another when they touch.

Explanation:

To determine the correct answer, we refer to the definitions provided on the left. The text states: "Work output is the amount of work done by the machine." We analyze each option:

• The first option ("The amount of work put into a machine") matches the definition of work input, not output.
• The second option ("The amount of work done by the machine") aligns with the definition of work output.
• The third option describes friction, not work output.

Answer:

The amount of work done by the machine.