When someone was shooting indoors with the window as the background, he happened to take a small stone falling from a height outside the window. It is known that the exposure time of this photography

When someone was shooting indoors with the window as the background, he happened to take a small stone falling from a height outside the window. It is known that the exposure time of this photography is 0. According to the proportional relationship, 4cm:100cm =1.6cm: l.

Then l = 40 cm = 0.4 m.

The instantaneous speed of stone ingestion is V = L T = 0.40.02m/s = 20m/s m/s.

So h = v22g = 400 20m = 20m.

So, this stone fell from 20 meters.