The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation is energy that travels and spreads out as it goes  the visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of electromagnetic radiation.
According to my doctor, 4 hours. You can switch them up. Take acetaminophen, (Tylenol), then wait 4 hours and take Ibuprofen, wait another 4 hours and take acetaminophen and sâ¦o on.
If whatever pain you're experiencing wasn't adequately controlled by the ibuprofen you took earlier, you could take 500 mg acetaminophen along with 800 mg ibuprofen every eight hours. If your pain lasts for more than a few days you should see a doctor.