So sorry , i will give whoever does all of these brainlist . :)

1. constant speed is a steady speed from start to finish, instantaneous is not constant from start to finish.

2. The average speed of the marble is 5 m/s  (meters per second).

3. Rider 1 will arrive at the destination before Rider 2.

Hope This Helps!  : )

the answer is:

carbon dioxide

c. the initial amount of money placed in the savings account