Joni runs several laps around a 400-meter track. Identify each phrase as defining a Constant Quantity, Changing Quantity, or Not a Quantity.
1. The time elapsed since Joni started running.
2. The time it took Joni to run the first lap.
3. The straight-line distance from Joni to her starting point.
4. The 400-meter track.
5. The distance Joni ran when she had finished two laps.