Question

Find evidence of three forces around your home

Answer 1

Pulling open a door, your weight, and a magnet on your refrigerator

Answer 2

-- Last night, I found one of my dogs sleeping in my bedroom.  My hypothesis is that he used the force of his legs to defy gravity, and lift his body up the stairs.

-- Before he could do that, though, he had to open the gate at the bottom of the stairs.  Sure enough, I found the gate open.  This was all the evidence I needed to revise my hypothesis ... My dog must have also applied the force of his nose to open the gate.

-- When I climbed up onto the bathroom scale this morning, I was startled by the sounds of grinding gears and metal screeching against metal inside the scale, and then the "whirrrr" as the display rose to dizzying heights with numbers that I never saw before.  

These sights and sounds could only be evidence of the force of gravity. EITHER I busted the delicate scale by jumping onto it too hard, OR ELSE I have gotten sloppy fat.  In either case, that sickening experience was the direct result of the force of gravity acting on my mass in a downward direction, toward the center of the Earth.