Today, my AP Physics teacher presented me with the following questions, and I couldn’t figure 'em out.
If a person undergoing an MRI had a steel plate in his body, how would we figure out the force exerted on the steel? (I’m pretty sure that people with metal plates don’t undergo MRIs…)
What’s the most common metal used for reinforcing bones, considering allergic reactions and corrosion? And what are the components of the metal?
Any help would be appreciated.
Can’t help you with the first question, but I can take a stab at the second.
Having watched every episode of The Operation on TLC, it seems that the most common material used for pinning and plating bones is stainless steel; titanium is used occasionally, but is quite a bit pricier than stainless.
I’m pretty certain the metal used in surgical reconstruction is titanium, due to light-weight, strength, and chemical inert-ness.
In an MRI, such a plate probably would be safe, because titanium is non-magnetic. But Vets with shrapnel, and metal workers are advised never to go neat an MRI, because the iron and steel would definately rip through the flesh.
F=MA, so could you just measure how far they flew off the table before they hit the ground?
Sorry.
More seriously, the answer more likely lies in measuring the magnetic field, along with the size (mass?) and magnetism of the plate. FWIW, my pin is stainless; others are titanium. I don’t know who Newark Wire is, but here’s their table of stainless steel grades if you want to browse it. None of the grades look very magnetic to this layman.
Get out your physics book.
Look up the equations for calculating magnetic force.
Use the mass of the steel plate. If no mass is given but size is (dimensions), then use the density to calculate the mass.
Hint: the magnetic field strength should have something to do with B.
(Any more, and I’d have to go look up the physics book, too.)