Final answer:
The mechanical advantage of a machine is how much it multiplies the applied force, considering energy losses such as friction. Ideal mechanical advantage assumes no friction, unlike actual machines where efficiency is also considered. Machines reduce the necessary input force through mechanical advantage, aiding in various tasks.
Step-by-step explanation:
The mechanical advantage of a machine is the amount by which a machine multiplies the force applied to it when accounting for energy lost due to friction. Simple machines such as levers, gears, pulleys, wedges, and screws can multiply or augment an input force, making it easier to perform a job with less effort. The mechanical advantage is determined by dividing the magnitude of the output force by the input force. An ideal mechanical advantage (IMA) assumes no energy loss to friction, which isn't the case in real machines where some energy is always converted to heat due to friction, thus reducing the efficiency of the machine.
Complex machines are combinations of two or more simple machines, and they also have a mechanical advantage and efficiency. While the mechanical advantage looks at the force multiplication, the efficiency of a machine is the ratio of output work to input work, expressed as a percentage, reflecting how well the machine conserves the mechanical energy that is put into it.
Even with the presence of friction and the resulting loss of energy, machines are invaluable tools because they reduce the input force needed to accomplish tasks, leveraging mechanical advantage to aid in various applications.