Air is a poor conductor of heat. The air trapped between the two panes is a pretty good <em>insulator</em>. It does a lot to prevent heat from flowing through the windows ... keeping heat IN during the Winter, and OUT during the Summer.
The answer I'm pretty sure is 3
Static electricity<span> is a </span>buildup<span> of </span>electric<span> charges on objects. Charges </span>build up<span> when negative </span>electrons<span> are transferred from one object to another. The object that gives </span>up electrons<span> becomes positively charged, and the object that accepts the </span>electrons<span> becomes negatively charged. This can </span>happen<span> in several ways</span>
Sodium (Na) is very reactive because it does not have a full valence shell.
<span>So we want to know which statement is true for the body of mass m=2000kg that is lifted to a height of h=15m in t=15 s. Lets calculate each of the following: Gravity force on the body is F=m*g=2000*9.81=19620 N so a is FALSE. Potential energy of the body when it is lifted to the height of 15 m is Ep=m*g*h=2000*9.81*15=294300 J so b is FALSE. Work to lift the body is: W=Fg*h=2000*9.81*15= Ep=294300 J so c is FALSE. Power P=W/t=294300/15=19620 W So d is TRUE. </span>