To understand the science behind many of the procedures it helps. Physics covers sound and light waves, the science behind sonograms, CAT scans, MRI's, and x-rays for starters. Then theres understanding the science of nuclear medicine, and that also falls in the physics category. Understanding forces, and how they act on a human body, electricity, and even simple gravity, go far in understanding the potential and actual injuries people suffer from accidents. Nursing is more than just working with the here and now of the patient, it's also understanding how you got there, and where you can expect to go in future. It may not be useful everyday, but it will be comforting to patients if you can explain the science behind the tests. Otherwise, you will look like an uneducated person and won't inspire much confidence in your patients.