Answer:
After 2 seconds the velocity of the object is 0 m/s.
Explanation:
The velocity at 2 seconds later can be calculated as follows:

Where:
: is the velocity at 2 seconds
: is the initial velocity = 20 m/s
g: is the gravity = 10 m/s²
t: is the time = 2 s
Hence, the final velocity is:

This value (0 m/s) means that the object has reached the maximum height.
Therefore, after 2 seconds the velocity of the object is 0 m/s.
I hope it helps you!