Doctors use radioactive sources as tracers for medical imaging. The table below shows the properties of some radioactive sources. Which source would be the best to use for a tracer that must be injected
into the body?
Enter your answer as a number
Radioactive source
Type(s) of
radiation emitted
Half-life
1
gamma
7 weeks
2
beta
3 days
12 minutes
3
alpha and gamma
4
gamma
23 minutes
5
alpha
4 hours

If jill was traveling at 300 miles in 4 hours due south what was his velocity in miles per minute a) 75 miles per hour due south b) .02 miles per second due south c) .5 miles per second due south d) 1 mile per hour due south

To understand the electric potential and electric field of a point charge in three dimensions consider a positive point charge q, located at the origin of three-dimensional space. throughout this problem, use k in place of 14? ? 0. part adue to symmetry, the electric field of a point charge at the origin must point from the origin.answer in one word.part bfind e(r), the magnitude of the electric field at distance r from the point charge q.express your answer in terms of r, k, and q. part cfind v(r), the electric potential at distance rfrom the point charge q.express your answer in terms of r, k, and q part dwhich of the following is the correct relationship between the magnitude of a radial electric field and its associated electric potential ? more than one answer may be correct for the particular case of a point charge at the origin, but you should choose the correct general relationship. a)e(r)=dv(r)drb)e(r)=v(r)rc)e(r)=? dv(r)drd)e(r)=? v(r)r

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?