Gather a variety of items of different shapes, weights, and materials, like a feather, a piece of paper, a small rock, an eraser, a ball, or anything else that isn't too heavy or won't be damaged by being dropped. Have your child feel and hold each item. Then drop the items one at a time from a table or porch onto a relatively flat surface.
How does each item move on the way down? Does it go straight down? Does it "float" down? Does it move quickly or slowly?
If your child enjoys this activity add some new items. Be sure to invite your child to choose some. As you add each new item, have your child touch it and hold it first and then try to predict how it will drop.