Step-by-step explanation:
It is given that, the force of gravity pulls down on your school with a total force of 400,000 N.
The force of gravity is given by the formula as follows :
F = mg
m is mass and g is the acceleration due to gravity
Mass of an object remains same always. But if the mass of your school becomes twice of the initial mass, the force of gravity pulling down on your school would be exactly twice.