Answer:
The acceleration of the skydiver assuming that it is constant due to the parachute is -5
.
The upwards force exerted during that time is 888 N.
Step-by-step explanation:
The skydiver weighs 588 N , this means that mg=588 N, where m is the mass of the skydiver.
Initial Velocity(u)=45 m/s
Final Velocity(v)=25 m/s
Time elapsed=4 s
a=??
Applying first equation of motion,

25=45 + 4a
4a=-20
a=-5

The acceleration of the skydiver assuming that it is constant due to the parachute is -5
.
From the FBD attached we get that
F-mg=m x a
F-588=300
F=888 N
The upwards force exerted during that time is 888 N.