Video Transcript
Three objects are shown. The objects are identical, except
that object A is radioactive. The distance between object A and
object B is the same as the distance between object B and object C. Radioactive contamination cannot
occur over distances greater than the distance between objects that are next to each
other. Would object C eventually become
radioactively contaminated?
The question asks us to think about
how objects become radioactively contaminated.
First, let us recall that an object
radioactively contaminates another object by transferring radioactive material to
the other object. Let’s first look at the distances
between the objects. We see that the objects are equally
spaced along the line. The question states that
radioactive contamination cannot occur at a distance greater than the spacing
between objects. We see then that object A can
contaminate object B directly, but object A cannot contaminate object C
directly.
The question asks if objects C will
be radioactively contaminated. We know that object A can
contaminate object B because object B is at a distance from object A within which
radioactive contamination can occur. It is very important to understand
that if object B is radioactively contaminated, object B has radioactive material
transferred to it from object A. The radioactive material
transferred to object B can now be transferred to any other object within the
distance that it is possible to transfer radioactive material.
Object C is at a distance from
object B that is short enough that radioactive material from object B can transfer
to object C. So we see that the correct answer
is yes, object C will become radioactively contaminated.
