Final answer:
AM radio waves have the longest wavelengths among cell phones, AM radio, and infrared light, with wavelengths ranging from over a meter to hundreds of meters.
Step-by-step explanation:
To answer the question of which type of electromagnetic radiation has the longest wavelengths – cell phones, AM radio, or infrared light – we must compare each one's typical wavelength range. Among the options provided, AM radio waves have the longest wavelengths. With wavelengths that can range from over a meter to hundreds of meters, AM radio clearly has larger wavelengths compared to the other types of radiation in question. Cell phone signals fall into the category of microwaves and radio waves, which are generally shorter than the AM radio waves and typically less than a meter. Infrared light has even shorter wavelengths, which are longer than visible light but shorter than microwaves, typically ranging from about 700 nanometers to about 1 millimeter.