Final answer:
A machine is a force multiplier when the load is greater than the effort, which is true. Simple machines, such as levers and pulleys, have a mechanical advantage that allows heavier loads to be lifted with less effort. However, their efficiency is always less than 100 percent due to energy losses like friction.
Step-by-step explanation:
The statement that a machine is a force multiplier when the load is greater than the effort is true. A force multiplier, such as a simple machine, allows us to lift heavier loads with less effort. Simple machines include levers, pulleys, and inclined planes, among others. These devices have a mechanical advantage (MA), which is the ratio of the output force to the input force. When the mechanical advantage is greater than one, the output force (load) will be greater than the input force (effort), thereby making the machine a force multiplier.
Moreover, it's important to note that the efficiency of a simple machine is always less than 100 percent. This is due to the fact that a fraction of the input work is always converted to heat due to friction, preventing the machine from being perfectly efficient. Efficiency is the ratio of output work to input work, highlighting the energy conservation aspect of machines even though they cannot do more work than the energy put into them.