If an object is dropped from rest off a 10.5m high building, how long does it take to hit the ground?

We can calculate the time it takes for the object to hit the ground by using the following equation:

where S=10.5 m is the initial height of the object, is the free-fall acceleration and t is the time. Re-arranging the equation, we can solve for the time:

the area between the graph and the t axis

the maxium height is 34m/s