Greetings!
Firstly, to find speed you need to remember the speed formula:
Speed = Distance ÷ Time
You can do it by doing 2800 ÷ 2 but that gives m/h (metres per hour)
So to convert hours into seconds, you multiply 2 by 7200 (amount of second in 2 hours:
2 * 7200 = 14400 seconds
Now we can do distance ÷ time by plugging the values in:
2800 ÷ 14400 =
≈0.194
So the average speed is 0.194m/s (metres per second)
Hope this helps!