Subject: why is some plastic playground equipment hotter than metal?

My son Tom sent this question in a week ago, but given that he didn't get a 
number back I am wondering if he did something incorrect on the form.  So I'll 
send it again for him.

Why is it that some plastic playground equipment, such as a slide, is hotter 
than the metal equipment around it?  This is even if the plastic is a light 
color and the metal is darker?  Tom has checked this with a thermometer on 
several pieces, and it is true; on, say, a 20 C day the metal will be 20 C and 
the plastic may be 30 C.  We will have to wait until December to check in the 
real heat of the summer.  I suspect that the answer is that all things being 
equal, it shouldn't be.  However, differences in mass and shape mean that the 
plastic piece heats up faster.  But I don't know that I am correct.

Thanks.

Scott (Tom's dad)

Re: why is some plastic playground equipment hotter than metal?