Question

When a real simple machine (as opposed to an ideal simple machine) is used to do work, the work input is

A) independent of
B) equal to
C) less than
D) greater than

Answer 1

When using a real simple machine, the work input is greater than the work output because of energy losses, typically due to friction.

Step-by-step explanation:

When a real simple machine is used to do work, the work input is greater than the work output due to the presence of factors such as friction that cause energy losses. Simple machines like levers, gears, pulleys, wedges, and screws make work easier by allowing us to exert less force, but at the cost of having to apply the force over a greater distance. The concept that the work input must be greater than the work output in real-world applications comes from the fact that no machine can have an actual mechanical advantage equal to the ideal mechanical advantage (IMA) because some of the energy exerted is always lost as heat due to friction. Therefore, the efficiency of a machine is the ratio of the work output to the work input, and it is always less than 100 percent because of these losses.