Some cars are 100 percent efficient at converting energy from gasoline to energy of motion. true or false.

False

Explanation:

100 efficiency is a myth and is termed as an ideal system. In real life there is nothing such as an ideal system.

Every machinery, system or engine follows the conservation of energy but are not 100 percent efficient. The amount of energy produces by gasoline is not only used to carry out the mechanical work done but also dissipated in form of heat. This generated heat reduces the efficiency of the system thus not making it an ideal engine of car.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it