[Potironette]

Is voltage the joules of PE changed to...some other energy...as charge moves from one point to another?

Is sound how humans perceive kinetic energy?

My exact sentences were:
"After the war, a booming economy that made televisions a household staple made white middle-class Americans more vulnerable to food advertisements."
I guess I was referring to the set of middle-class Americans who were white.
I was told that it was without the comma, but I don't know what the difference is.

"A dark and greasy plastic film called “Saran” was developed by the Dow Chemical Company during the war for soldiers to spray on fighter planes to protect against sea spray."
I was describing one type of film. So, I suppose it's with a comma?
But is there a connection between this and "white, middle-class Americans"?