Which of the following is an example of a wheel and axle?

A wheel and axle is a simple machine that consists of two circular objects of different sizes, with the wheel being the larger component and the axle being the smaller, cylindrical part that is attached to the wheel. When the wheel is turned, the axle moves in conjunction with it, allowing for the transfer of motion and force.

The steering wheel serves as a prime example of a wheel and axle system. When a driver turns the steering wheel, the larger wheel rotates, which in turn causes the axle and the components connected to it, such as the steering column and ultimately the vehicle's wheels, to pivot. This action allows the driver to control the direction of the vehicle effectively.

In contrast to the steering wheel, a hammer is a tool designed primarily for striking, a pulley is used to lift or lower loads by changing the direction of the force applied, and a lever is a simple machine that amplifies force but does not involve the combination of a circular wheel and axle. Each of these alternative options operates under different mechanical principles and does not exemplify the wheel and axle mechanism.