It's not possible to multiply energy by any means.
All that machines do is to alter the application of force.
If a lever has a 2:1 ratio, you move your end 2 feet, while the load moves 1 feet. The advantage is, for a 50 pound load, you only have to exert kgpounds force, so (your end) 2 x 25 = (load) 1 x 50.
Force
Does not multiply energy. Work done or energy used (force * distance) remains the same at both ends. Force or torque can be increased or decreased depending on mechanical advantage. It can change the direction of the force or torque.
crowbar &seesaw
An electric motor is not a simple machine, because it uses electric energy, which is not mechanical energy, which powers simple machines.
NO. No system can put out more Energy than is put into it. That would violate the 2nd Law of Thermodynamics. However, a simple machine, like a lever can put out more Force than is put in.
The efficiency of a machine is found by considering the useful energy or work that comes out of it, and dividing this by the work that you put into it. Multiply by 100 to get the answer in terms of percentage. You should never get more than 100% efficiency, or 100%, since energy will be lost (to heat caused by friction for example).
you have to multiply the individual mechanical advantages of all the simple machines that make up the compound machine.
you have to multiply the individual mechanical advantages of all the simple machines that make up the compound machine.
you have to multiply the individual mechanical advantages of all the simple machines that make up the compound machine.
That isn't possible, not with a simple machine and not with a complicated machine, since otherwise, conservation of energy would be violated.
yes. yes. no
A car is not a simple machine because it has hundreds of moving parts, including dozens of forms of simpler machines. Also, a simple machine converts only mechanical energy (kinetic energy) while a full-size car is powered either chemically or electrically.