One of the most basic properties of energy is that it can be transformed (changed in type) and transferred (moved between points in space).

When you connect batteries to an IQ Key machine, the chemical energy stored in the batteries is transformed into electrical energy. The motor in an IQ Key machine then converts the electrical energy into mechanical energy.

The mechanical energy is used to move parts, like wheels or a fan. In order to move four different wheels at four different corners of a car, for example, we need to be able to transfer that energy to each location from the motor. In this case, we can use gears and gear shafts. 

Knowing how energy flows through a system is important when building mechanical devices.

Torque is a rotational force—a force that turns a solid object around a pivot point. For example, if you want to tighten a bolt with a wrench, you need to apply torque to rotate the bolt around the threaded rod (pivot point).

Torque is applied by pushing or pulling on an object around its pivot point. This distance from the pivot point to where you push or pull is called the radius. Both the amount of force and the location of the force determine the amount of torque being generated. If you turn a wheel from its outer edge, it will have a greater torque than if you turn it closer to its axle. Here is the mathematical formula for finding torque:

Force x Radius = Torque

When force is applied over a distance, we call it work. In this case, distance refers to how far an object moves while being pushed or pulled by an applied force.

Force x Distance = Work

Work is a form of energy. Like other forms of energy, it is commonly measured in joules (J) (after the physicist James Prescott Joule). One joule is the amount of work done when a force of one newton is applied over a distance of one meter.