Air is an insulator. however, in winter you might experience a spark when your fingers touch a doorknob. briefly explain why this happens. use 2 content related sentences.

This happens because of the static electricity.  

Explanation:

Static electricity is the type of electricity that is generated in bodies due to friction. In the doorknob, different persons open and close them to open and close the door. This results in the generation of static electricity due to friction.

As the friction increases the static electricity increases. When after a considerable time the doorknob is touched, a mild shock or a crackling sound can be heard from the knob. In winter it’s increases because of the increase in changes of friction.  

Image shown below

Explanation:

There are no options, but I'll provide a graph, so you can compare with your own options and answer the question.

Graph expression of a vector

If we know the coordinates of the start and endpoint of a vector, then we can easily sketch it in the XY plane by drawing a straight line directed from the start point to the final point.

The vector starts at (0,0) and ends at (-4,2). Locating both points in the cartesian plane and joining them with a straight line ending with an arrow to state its direction, we'll get the drawing shown in the image below