Construct an hypothesis <em /><em>(Because </em>the magnet wasn't attracted to the door, the door must be non-magnetic.) He has already made an observation (the magnent didn't stick), and already asked a question (<em>Why </em>didn't the magnent stick). However, he has not explained the results (there is no experiment yet).
Your calculator will return a result of 11.76cm^2
The correct answer must have 2 significant figures:
Answer : 12cm^2
False, you'd have less pressure if you increased the area.
P=F/A, you're dividing by A. If you say, doubled A, you'd have only half the pressure.
Electrostatic repulsion is the force between two charges having the same sign, that tends to separate them further. The force is proportional to the product of the charges, and inversely proportional to the square of the distance between them.
C. The electrostatic force is only repulsive and acts over shorter distance.