Question

On a roller coaster, a student experiences an apparent weight of 1250 N while accelerating at 2.3 m/s^2 [U]. What is the students mass?

Answer 1

In which direction is the student accelerating? It matters.

If accelerating upward,
1250=m(9.8+2.3)
if acceleralting downward
1250=m(9.8-2.3)

If in any direction other than upward or downward, it will be between these numbers.