The independent variable in this problem would be the different types of shower cleaner. The dependent variable would be the shower tiles.
Calcium has 2 valence electrons
Magnets are attracted when each of the different sides, most commonly known as "North" and "South", are facing each other. They repel when North and North, or South and South are facing each other.
Answer:
We have to show surface area
,with few conditions that is by considering Force
and Pressure
to be respectively.
Explanation:
The atmospheric pressure is
on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is
.
Now to calculate surface area we can find it from
and re-arranging it to.

So plugging the values,
Surface area 
Hence from the above calculations we can say that surface area is
.
So the surface area of an average person can be said to have
, using the concept of pressure and force.