A person weighing 0.9 kN rides in an elevator
That has a downward acceleration of 3 m/s2.
The acceleration of gravity is 9.8 m/s2 .
What is the magnitude of the force of the
Elevator floor on the person? Answer in units
Of kN.

Bit more involved than the other one, but all you need is F=ma again.
Let me know if you get stuck. Show your working