Write an equation for the following statements:
1.) The perimeter (P) of a square is directly proportional to the length of its sides(s).
2.) The circumference (c) of a circle is proportional as the diameter (d).
3.) y is proportional to the square root of u.
4.) The cost of electricity (C) varies directly as the number of kilowatt-hour consumption (h).
5.) The weight (W) of an object is directly proportional to its mass (m).