Duke Zhou's bell struck.

From h1=1/2at12, it is concluded that: 4.9 =1/2a *12a = 9.8m/s2, indicating that the falling of an object is a free-falling motion.

When it takes 10 second to reach the ground, the original height of the object from the ground is H = 1/2 at 2 =1/2 * 9.8 *10 2 = 490 m.

The object was originally 490 meters above the ground.