How Does Opening a Parachute Affect a Falling Parachutist's Motion?

[checkmarks]

Homework Statement

A parachutist of mass 70kg, in free fall at 136 km/h, opens a parachute. if the chute creates a 895 N air resistance force and the parachutist is being pulled down by a force of gravity at 686 N
a) find hte acceleration of the parachutist
b) how far does she fall in 5.0 s?

Homework Equations

Fnet = ma, d = v1t + 1/2at^2

The Attempt at a Solution

First i determined part A and i got the answer 3.0 m/s^2 [up]. which is correct in the answer key.
then i used the equation d = v1t + 1/2at^2, converting 136 km/h to m/s
d = v1t + 1/2at^2
d = 37.7 m/s(5s) + 1/2(3 m/s^2)[(5s)^2]

and i got 226.4 m. the correct answer is 150m. i don't know what i did wrong. i then tried using the acceleration due to gravity, 9.81 m/s^2 because it is a freefall but the answer was still wrong.
please help!

 

[Doc Al]

The person's initial speed is downward, thus negative.