A simple explanation might be weight (or mass) acting through a distance (inches, centimeters, etc) creates a force.
Examples:
1.) On a see saw (or teeter-totter) a 100 lb person sitting a 2' from the balance point (or fulcrum) will create a force of 200 lbs.- ft (often and very incorrectly stated as ft-lbs*) match 100 lbs x 2 feet= 200 lb.-ft). A 50 lb. person sitting at the other end of the see saw sitting at 4 feet from the balance point will create the same force and both persons will be in perfect balance. The math 50 lbs. x 4" = 200 lbs. ft.
2.) If the 50 ponder moves 6 feet away from the balance point he will create a greater force (or 300 lb.- ft.) and raise the larger person in the air.

* Yes this is a fact. As they say I are an engineer by degree. Also, a battery sitting on concrete will not discharge any faster than a battery stored on wood, plastic, cardboard, etc. They both will discharge at the same rate. Concrete is not a conductor of electricity but humidity in the air is. Batteries from little lawn tractor batteries to forklift 1200 am/hr batteries are recommended to be charged at least every 6 months if not put into service to 1.) boost voltage to spec 2.) add water that may have evaporated below the top of the plates 3.) to prevent plate sulfating