Is Gravitational Acceleration Positive or Negative in Upward Motion Problems?

[jamiebean]

Homework Statement

A boy throws a stone vertically up with a speed 24.6 m/s. Assuming that the stone's motion is affected by the gravitaional acceleration only (acceleration g=9.8ms-2). What is the displacement in m between the stone's position at time 3.8 s and its initial position? (hint: displacement has a sign "+" or "-", the canvas system can accept signed input. upward direction is "+" and the downward direction is "-", gravitation acceleration is negative in sign)

Relevant Equations

d=vi x t + (at^2)/2
gravitation acceleration= -9.8

I attempted the question with
d=vi x t + (at^2)/2
gravitation acceleration= -9.8
and I got the solution of 22.724.

Should I use the value of -9.8? or should I just use 9.8?

should I use the equation above? I feel like what I am calculating is not displacement but distance...
thank you

 

[PeroK]

The question says that upwards is positive. That means that the gravitational acceleration is ...

 

[jamiebean]

The question says that upwards is positive. That means that the gravitational acceleration is ...

thanks a lot! I have got this problem right!love yah